General Aptitude MCQ Quiz
100 Comprehensive Questions with Explanations
1. To access properties of an object, the mouse technique to use is ?
Explain:- The mouse technique used to access properties of an object is typically right-clicking.
2. There are two examination rooms A and B. If 10 students are sent from A to B, then the number of students in each room is the same. If 20 candidates are sent from B to A, then the number of students in A is double the number of students in B. The number of students in room A is:
Explain:- Solving equations: x-10=y+10 and x+20=2(y-20), we get x=100.
3. If a - b = 3 and a² + b² = 29, find the value of ab.
Explain:- 2ab = (a²+b²) - (a-b)² = 29 - 9 = 20 ⇒ ab = 10.
4. The product of two numbers is 120 and the sum of their squares is 289. The sum of the numbers is:
Explain:- (x+y)² = x²+y²+2xy = 289+240=529 ⇒ x+y=23.
5. The salaries of A, B, and C are in the ratio 2 : 3 : 5. If their increments are 15%, 10% and 20% respectively, then what will be the new ratio of their salaries?
Explain:- A=2k, B=3k, C=5k. After increment → A=23k/10, B=33k/10, C=6k. Ratio=23:33:60.
6. A and B entered into partnership with capitals in the ratio 4 : 5. After 3 months, A withdrew 1/4 of his capital and B withdrew 1/5 of his capital. The gain at the end of 10 months was Rs. 760. A's share in this profit is:
Explain:- A:B = (12x+21x):(15x+28x)=33:43. A’s share = 760 × 33/76 = Rs. 330.
7. What is R's share of profit in a joint venture?
Explain:- R’s investment is not given, so ratio incomplete. Data inadequate.
8. A alone can do a piece of work in 6 days and B alone in 8 days. A and B undertook to do it for Rs. 3200. With the help of C, they completed the work in 3 days. How much is to be paid to C?
Explain:- A:B:C = 4:3:1. C’s share = 3200 × 1/8 = Rs. 400.
9. A goods train runs at 72 kmph and crosses a 250 m platform in 26 sec. What is the length of the train?
Explain:- Speed=20 m/s. Distance=20×26=520 ⇒ Length=520-250=270 m.
10. If log₁₀2 = 0.3010, then log₂10 is equal to:
Explain:- log₂10 = 1 / log₁₀2 = 1/0.3010 ≈ 3.322 ≈ 1000/301.
11. An error 2% in excess is made while measuring the side of a square. The percentage of error in the calculated area of the square is:
Explain:- Error in area = (2×2% + (2%)²) = 4.04%.
12. In a shower, 5 cm of rain falls. The volume of water that falls on 1.5 hectares of ground is:
Explain:- Volume = Area × Depth = 15000 × 0.05 = 750 m³.
13. What is the volume of a cube if the area of each face is 64 m²?
Explain:- Side = √64 = 8. Volume = 8³ = 512 m³.
14. The reflex angle between the hands of a clock at 10:25 is:
Explain:- Hour hand at 10h25 = 312.5°. Minute hand = 150°. Reflex angle = 360 − 162.5 = 197.5°.
15. At what time between 4 and 5 o'clock will the hands of a watch point in opposite directions?
Explain:- Hands must be 180° apart. Time = 54 6/11 min after 4.
16. A 12% stock yielding 10% is quoted at:
Explain:- To earn Rs. 10, invest Rs. 100. To earn Rs. 12, invest 120 ⇒ MV = 120.
17. In how many ways can the letters of the word 'DETAIL' be arranged such that the vowels occupy only the odd positions?
Explain:- Vowels (3) in odd places = 3! = 6. Consonants (3) = 3! = 6. Total = 36.
18. Two dice are tossed. The probability that the total score is a prime number is:
Explain:- Total = 36, favourable = 15. P=15/36=5/12.
19. An observer 1.6 m tall is 20√3 m away from a tower. The angle of elevation to the top is 30°. The height of the tower is:
Explain:- Height = 1.6 + (20/√3)tan30° = 1.6+20 = 21.6 m.
20. Find the odd one out: 1, 4, 9, 16, 23, 25, 36
Explain:- All are perfect squares except 23.
21. A man completes a journey in 10 hours. He travels the first half at 21 km/hr and the second half at 24 km/hr. The total journey is:
Explain:- Distance = (2xy / (x+y)) × Time = (2×21×24)/(45) × 10 = 224 km.
22. The least number which when divided by 12, 15, 20 and 54 leaves the same remainder is:
Explain:- LCM of 12,15,20,54 = 540. Required no = 540 + remainder. Hence 544.
23. A father is 3 times as old as his son. After 15 years, the father will be twice as old as his son. The father’s present age is:
Explain:- Let son = x, father = 3x. Then 3x+15 = 2(x+15). Solve → x=15, father=45.
24. If 2994 ÷ 14.5 = 172, then the value of (2994 ÷ 0.5) – (172 × 5) is:
Explain:- (2994÷0.5) − (172×5) = 5988 − 860 = 2700.
25. If log 27 = 1.431, then the value of log 9 is:
Explain:- log 9 = log(3²) = 2 log3 = 2×0.477 = 0.954.
26. If log 125 = 2.079, then the value of log 5 is:
Explain:- log125=log(5³)=3 log5 → log5=2.079/3=0.693.
27. √0.000081 is equal to:
Explain:- √0.000081 = √(81×10⁻⁶) = 9×10⁻³ = 0.009.
28. The largest 4 digit number exactly divisible by 88 is:
Explain:- 9999 ÷ 88 = 113.62 → 113×88 = 9944.
29. 252 can be expressed as a product of primes as:
Explain:- 252 = 2² × 3³ × 7.
30. The least perfect square divisible by 3, 4, 5, 6 is:
Explain:- LCM(3,4,5,6)=60. Least perfect square multiple=900.
31. The difference between the squares of two consecutive numbers is 45. The smaller number is:
Explain:- Difference = 2n+1 = 45 ⇒ n=22.
32. The smallest number which when diminished by 7 is divisible by 12, 16, 18, 21, 28 is:
Explain:- LCM=1008. Required number=1008+7=1015. Check → Correct is 1007.
33. The least multiple of 7 which when divided by 2, 3, 4, 5, 6 leaves remainder 1 is:
Explain:- LCM(2–6)=60. Required no.=60k+1. Multiple of 7 → 301.
34. A train covers 180 km at a uniform speed. If the speed had been 10 km/hr more, it would have taken 30 min less. The speed is:
Explain:- Solve: 180/x − 180/(x+10)=0.5 → x=40.
35. A batsman has a certain average of runs in 11 innings. In the 12th innings, he scores 132 runs, thereby increasing his average by 5. The average after 12 innings is:
Explain:- Let avg=x. 11x+132=12(x+5) → x=33. New avg=38.
36. The average of 20 numbers is zero. Of them, at most, how many may be greater than zero?
Explain:- If 19 are positive, sum of them can be balanced by 1 large negative number.
37. A student finds the average of 10, 2-digit numbers. By mistake, he considers one number as 64 instead of 46. His average is larger by:
Explain:- Error=18. Effect on avg=18/10=1.8.
38. A card is drawn at random from a pack of 52 cards. The probability that the card drawn is neither a spade nor a king is:
Explain:- Total 52. Spades=13, kings=4, but 1 overlap=16. Not spade/king=36. Probability=36/52.
39. The probability of getting at least one head in two tosses of a coin is:
Explain:- P(at least one head)=1−P(no head)=1−1/4=3/4.
40. The probability that a leap year has 53 Sundays is:
Explain:- Leap year=366 days=52 weeks+2 days. Extra days can be Sunday+Monday (2/7 chance).
41. A shopkeeper expects a gain of 22.5% on his cost price. If in a week, his sale was of Rs. 392, what was his cost price?
Explain:- Let cost price = 100. Selling price = 122.5. Ratio CP:SP = 100:122.5 = 200:245. So, CP = (200/245) × 392 = Rs. 320.
42. A man buys a cycle for Rs. 1400 and sells it at a loss of 15%. What is the selling price of the cycle?
Explain:- Loss = 15% of 1400 = 210. SP = CP − Loss = 1400 − 210 = Rs. 1190.
43. A trader marked the price of an article 25% above the cost price and allowed a discount of 12%. What is his gain percent?
Explain:- Let CP = 100. Marked price = 125. After 12% discount, SP = 125 × 88/100 = 110. Profit = 10%.
44. If 40% of a number is equal to two-thirds of another number, what is the ratio of the first to the second number?
Explain:- Let first number = x, second = y. 40% of x = 2/3 y ⇒ 40x/100 = 2y/3 ⇒ x/y = 4/5.
45. If A is twice as good as B and together they finish a work in 14 days, then B alone can do it in:
Explain:- Let B do 1 work/day. A = 2 work/day. Together = 3 work/day. Work in 14 days = 42. So B alone = 42 days.
46. A tap can fill a tank in 12 hours. Another tap can empty the tank in 20 hours. If both are opened together, the tank will be filled in:
Explain:- Work in 1 hr = (1/12 − 1/20) = (5−3)/60 = 2/60 = 1/30. So time = 30 hrs. Wait correction → LCM=60. In 1 hr = 5−3=2 parts. Total=60 parts. Time=30 hrs. (Answer should be 30 hrs actually, check).
47. A boat can travel 20 km downstream in 2 hours, while it takes 4 hours to return upstream the same distance. What is the speed of the boat in still water?
Explain:- Downstream speed=20/2=10. Upstream=20/4=5. Boat speed=(10+5)/2=7.5. (Check again). Actually correct speed=7.5 km/hr.
48. A sum of money amounts to Rs. 660 in 2 years and Rs. 726 in 3 years at compound interest. The sum is:
Explain:- Ratio of amounts = 726:660 = 121:110. Rate=10%. So, Principal = 660 × 100 / 110 = Rs. 600.
49. A sum was put at simple interest at a certain rate for 2 years. Had it been put at 3% higher rate, it would have fetched Rs. 72 more. The sum is:
Explain:- Difference = P × 3 × 2 /100 = 72 ⇒ P = (72×100)/(6)=1200.
50. The difference between compound interest and simple interest on Rs. 2500 for 2 years at 4% per annum is:
Explain:- CI − SI = P × (r/100)² = 2500 × (16/10000) = Rs. 4.
51. A sum of Rs. 1550 is lent out in two parts. One at 8% simple interest and another at 6% simple interest. The total simple interest after 3 years is Rs. 300. The sum lent at 8% is:
Explain:- Let Rs. x be lent at 8%, then (1550 − x) at 6%. 3 years SI = (x×8×3/100) + ((1550−x)×6×3/100) = 300. ⇒ 24x + 279 − 18x = 3000 ⇒ 6x = 721 ⇒ x ≈ 800.
52. A man rows to a place 48 km downstream in 6 hours. He returns in 8 hours. The speed of the man in still water is:
Explain:- Downstream speed = 48/6 = 8 km/hr. Upstream speed = 48/8 = 6 km/hr. Speed in still water = (8+6)/2 = 7 km/hr. Correction: (48/6)=8, (48/8)=6 ⇒ (8+6)/2=7 km/hr. Final = 7.
53. A man can row 18 km downstream in 4 hours and return in 6 hours. The speed of the current is:
Explain:- Downstream speed = 18/4 = 4.5. Upstream speed = 18/6 = 3. Current speed = (4.5−3)/2 = 0.75. Correction: Actually current = (4.5−3)/2 = 0.75. Final = 0.75 km/hr.
54. A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?
Explain:- Speed = 60 × (1000/3600) = 16.67 m/s. Distance = Speed × Time = 16.67 × 9 = 150 m.
55. A train 125 m long passes a man, running at 5 km/hr in the same direction, in 10 seconds. The speed of the train is:
Explain:- Relative speed = Distance/Time = 125/10 = 12.5 m/s = 45 km/hr. Train speed = 45+5 = 50 km/hr. Correction: Actually = 50 km/hr.
56. A train 300 m long is running at a speed of 54 km/hr. It will cross a platform 500 m long in:
Explain:- Speed = 54 × (1000/3600) = 15 m/s. Distance = 300+500 = 800 m. Time = 800/15 ≈ 53.3 sec ≈ 53 sec. Closest option = 53 sec. (≈ 53).
57. A car travels at 60 km/hr and covers a distance in 8 hours. What is the distance travelled?
Explain:- Distance = Speed × Time = 60 × 8 = 480 km.
58. If 20 men can complete a work in 25 days, then 25 men can complete the same work in:
Explain:- Work = Men × Days = 20 × 25 = 500. So, 25 men → Days = 500/25 = 20 days.
59. A can do a work in 15 days and B in 20 days. They work together for 4 days, then A leaves. B will finish the remaining work in:
Explain:- A’s 1 day work = 1/15, B’s = 1/20. Together = 7/60. In 4 days = 28/60 = 7/15. Remaining = 8/15. B alone = (8/15) ÷ (1/20) = 160/15 ≈ 10.67 days. Closest = 11 days.
60. A can do a piece of work in 30 days, B in 40 days and C in 60 days. They work together for 8 days, then A leaves. In how many more days will the work be finished?
Explain:- A=1/30, B=1/40, C=1/60. In 1 day = 1/30+1/40
61. A and B can do a piece of work in 12 days. B and C can do it in 15 days. A and C can do it in 20 days. In how many days can A alone finish it?
Explain:- (A+B)=1/12, (B+C)=1/15, (A+C)=1/20. Add all → 2(A+B+C)=1/12+1/15+1/20 = 1/5. So (A+B+C)=1/10. Now A = (A+B+C)−(B+C) = 1/10−1/15 = 1/30. So A=30 days.
62. A sum of money triples in 20 years at simple interest. In how many years will it become 5 times?
Explain:- If it triples, then SI = 2P in 20 yrs ⇒ SI per year = 2P/20 = P/10. For 5P ⇒ SI=4P. Time=4P ÷ (P/10) = 40 yrs. Correction: Actually 40 yrs. Final=40.
63. A sum of Rs. 1200 amounts to Rs. 1680 in 4 years at simple interest. The rate of interest per annum is:
Explain:- SI = 1680−1200=480. Rate = (100×SI)/(P×T) = (100×480)/(1200×4)=10%.
64. A sum of money doubles itself at compound interest in 15 years. It will become eight times in:
Explain:- If it doubles in 15 yrs, then it becomes 8 times in 3 such periods (because 2³=8). Time = 15×3 = 45 yrs.
65. A sum of Rs. 500 amounts to Rs. 583.20 in 2 years at compound interest. The rate of interest is:
Explain:- Amount = P(1+r/100)². 583.20 = 500(1+r/100)² ⇒ (1+r/100)²=583.2/500=1.1664. So, 1+r/100=1.08 ⇒ r=8%.
66. A person invests Rs. 5000 at 12% per annum simple interest for 3 years. The interest earned is:
Explain:- SI = P×R×T /100 = 5000×12×3/100=1800.
67. A sum of money amounts to Rs. 9800 in 5 years and Rs. 12005 in 8 years at simple interest. The principal is:
Explain:- Difference in amount for 3 yrs = 12005−9800=2205 ⇒ SI for 3 yrs =2205 ⇒ SI per year=735. For 5 yrs SI=735×5=3675. Principal=9800−3675=8800.
68. A man invested Rs. 10000 in a scheme at compound interest at 10% per annum. The amount after 2 years will be:
Explain:- Amount = P(1+r/100)² = 10000×(1.1)²=12100.
69. The average of 20 numbers is zero. Of them, at most, how many may be greater than zero?
Explain:- Since average=0 ⇒ sum=0. If 19 numbers are positive, their sum can be balanced by one large negative number. So max=19.
70. The average of 10 numbers is 7. If each number is multiplied by 12, the average of the new set of numbers is:
Explain:- New average = old average × 12 = 7×12 = 84.
71. The average age of 30 students is 12 years. If the teacher’s age is also included, the average becomes 13 years. The age of the teacher is:
Explain:- Total age of 30 students = 30×12=360. With teacher = 31×13=403. Teacher’s age=403−360=43. Correction: final=43 yrs.
72. The average marks of 8 students in a class is 25. If one more student’s marks are added, the average increases to 26. The marks of the new student are:
Explain:- Total marks of 8 students=8×25=200. New total=9×26=234. Marks of new student=234−200=34. Correction: actual=34 (not in options, closest=35).
73. The average of five consecutive odd numbers is 61. The smallest number is:
Explain:- For 5 consecutive odd numbers, the average is the middle number = 61. So numbers are 57,59,61,63,65. Smallest=57.
74. A batsman has a certain average of runs for 16 innings. In the 17th inning he scores 85 runs, thereby increasing his average by 3 runs. His average after 17th inning is:
Explain:- Let old avg=x. Then total runs in 16 innings=16x. New avg=x+3 ⇒ total runs in 17 innings=17(x+3). So 16x+85=17x+51 ⇒ x=34. New avg=34+3=37.
75. The average of 25 numbers is 36. The average of the first 13 numbers is 32 and of the last 13 numbers is 40. The 13th number is:
Explain:- Total sum=25×36=900. Sum of first 13=13×32=416. Sum of last 13=13×40=520. Both include 13th twice. So 416+520−13th=900 ⇒ 13th=36.
76. The average weight of 40 students is 36 kg. If the teacher’s weight is included, the average increases by 1 kg. The weight of the teacher is:
Explain:- Total weight of 40 students=40×36=1440. New total=41×37=1517. Teacher’s weight=1517−1440=77.
77. The average of 7 consecutive even numbers is 24. The largest of these numbers is:
Explain:- For consecutive numbers, average=middle. Middle=24 ⇒ numbers are 18,20,22,24,26,28,30. Largest=30.
78. The average score of a class of 40 students is 60. If the average score of half the students is 50, what is the average score of the other half?
Explain:- Total score=40×60=2400. Half (20 students) avg=50 ⇒ sum=1000. Remaining 20 students sum=2400−1000=1400 ⇒ avg=1400/20=70.
79. The average of 12 numbers is 25. If each number is increased by 4, the new average is:
Explain:- New average = old average + 4 = 25+4=29.
80. The average marks obtained by 120 students is 35. If the average marks of boys is 30 and that of girls is 40, the number of boys is:
Explain:- Let boys=x, girls=120−x. Total marks=120×35=4200. Boys marks=30x, girls=40(120−x)=4800−40x. So 30x+4800−40x=4200 ⇒ −10x=−600 ⇒ x=60. Correction: Answer=60 boys.
81. The average age of a family of 5 members is 21 years. If the present age of the youngest member is 5 years, what was the average age of the family at the time of his birth?
Explain:- Present total age=21×5=105. 5 years ago, total=105−5×5=80 (since all were 5 years younger, youngest not born). Members=4. Average=80/4=20. Correction: Answer is 20 yrs (option C).
82. The average of 6 numbers is 8. The average of 4 of them is 5. What is the average of the remaining two numbers?
Explain:- Total sum=6×8=48. Sum of 4=4×5=20. Remaining sum=28. Average=28/2=14. Correction: 14 (not in options, closest=15).
83. The average of three numbers is 20. If two numbers are 16 and 22, the third number is:
Explain:- Total sum=3×20=60. Given two numbers=16+22=38. Third=60−38=22.
84. The average of 10 consecutive numbers is 25. The smallest of these numbers is:
Explain:- Average=25 ⇒ middle number=25. For 10 numbers, average is mean of 5th & 6th. So 5th=25, smallest=25−(5−1)=21.
85. The mean of 100 observations is 50. If each observation is increased by 5, the new mean is:
Explain:- New mean = old mean + 5 = 50+5=55.
86. The average of 5 numbers is 27. If one number is excluded, the average becomes 25. The excluded number is:
Explain:- Total sum of 5=5×27=135. Sum of 4=4×25=100. Excluded=135−100=35.
87. The average of 50 numbers is 38. If two numbers 45 and 55 are discarded, the average of the remaining numbers is:
Explain:- Total sum=50×38=1900. Removing 45+55=100. Remaining sum=1800. Numbers=48. Average=1800/48=37.5 ≈ 37.
88. The mean of 25 observations is 36. Later it was found that one observation 72 was wrongly taken as 27. The correct mean is:
Explain:- Wrong sum=25×36=900. Correct sum=900−27+72=945. Correct mean=945/25=37.8. Correction: Answer=37.8 (option B).
89. The average of 7 numbers is 50. If each number is multiplied by 5, the average of new numbers is:
Explain:- New average = old average × 5 = 50×5=250.
90. The average marks of 30 students in a class is 45. If the marks of one student is increased by 15, the average of the class increases by:
Explain:- Increase in total marks=15. Average increase=15/30=0.5.
91. The average of 11 numbers is 50. If the average of the first six numbers is 49 and that of the last six numbers is 52, the sixth number is:
Explain:- Total=11×50=550. First 6=6×49=294. Last 6=6×52=312. Both include 6th twice. 294+312−6th=550 ⇒ 606−6th=550 ⇒ 6th=56. Correction: Answer=56 (option B).
92. The average age of a class of 30 students is 14 years. If the teacher’s age is included, the average becomes 15 years. The teacher’s age is:
Explain:- Total of students=30×14=420. With teacher=31×15=465. Teacher=465−420=45. Correction: Answer=45 (option B).
93. The average of 15 numbers is 25. If each number is multiplied by 4, the average of the new numbers is:
Explain:- New average=old average×4=25×4=100.
94. The mean of 40 numbers is 38. If two numbers 45 and 55 are excluded, the mean of the remaining numbers is:
Explain:- Total sum=40×38=1520. Remove 100 ⇒ 1420. Numbers=38. Average=1420/38=37.37 ≈ 37.
95. The average age of a group of 10 students is 20 years. If one more student joins, the average increases by 1. The age of the new student is:
Explain:- Total for 10=10×20=200. New total=11×21=231. New student=31.
96. The mean of 20 numbers is 45. If each number is decreased by 5, the new mean is:
Explain:- New mean=old mean−5=45−5=40.
97. The average of 6 numbers is 10. If each number is multiplied by 2, the new average is:
Explain:- New average=old average×2=10×2=20.
98. The mean of 12 numbers is 42. If one number is added, the mean becomes 44. The added number is:
Explain:- Total for 12=12×42=504. New total=13×44=572. Added=68. Correction: 68 (not in options, closest 66).
99. The mean of 5 numbers is 18. If each number is increased by 2, the new mean is:
Explain:- New mean=old mean+2=18+2=20.
100. The average of first 10 natural numbers is:
Explain:- Sum of first 10 numbers=10×11/2=55. Average=55/10=5.5.
End of Quiz
