Quantitative Aptitude
Q.61
Medium
A shopkeeper sells an item at a loss of 12%. If the cost price is Rs. 500, what is the selling price?
A
Rs. 425
B
Rs. 430
C
Rs. 440
D
Rs. 450
Correct Answer:
C. Rs. 440
Explanation:
Selling Price = Cost Price × (1 - Loss%) = 500 × (1 - 0.12) = 500 × 0.88 = Rs. 440
Q.62
Medium
The speed of a boat in still water is 12 km/h. If the speed of the current is 3 km/h, what is the speed downstream?
A
14 km/h
B
15 km/h
C
16 km/h
D
18 km/h
Correct Answer:
B. 15 km/h
Explanation:
Speed downstream = Speed in still water + Speed of current = 12 + 3 = 15 km/h
Q.63
Medium
If (x + 2)² = 36, what is the value of x?
A
4 or -8
B
4 or 6
C
6 or -6
D
-4 or 8
Correct Answer:
A. 4 or -8
Explanation:
Taking square root: x + 2 = ±6. So x = 4 or x = -8
Q.64
Medium
A rectangular field has length 80 m and breadth 60 m. What is the cost of fencing it at Rs. 25 per meter?
A
Rs. 6,500
B
Rs. 7,000
C
Rs. 7,500
D
Rs. 8,000
Correct Answer:
B. Rs. 7,000
Explanation:
Perimeter = 2(80 + 60) = 280 m. Cost = 280 × 25 = Rs. 7,000
Q.65
Medium
The average age of 8 people is 35 years. If one person of age 45 leaves the group, what is the new average age?
A
32.14 years
B
33.57 years
C
34.2 years
D
35.5 years
Correct Answer:
B. 33.57 years
Explanation:
Total age of 8 people = 8 × 35 = 280 years. After removal: total = 280 - 45 = 235. New average = 235/7 = 33.57 years
Q.66
Medium
If x³ = 729, what is the value of x?
Explanation:
x = ∛729 = 9 (since 9 × 9 × 9 = 729)
Q.67
Hard
If a² + b² = 13 and ab = 6, what is the value of (a + b)²?
Explanation:
(a+b)² = a² + b² + 2ab = 13 + 2(6) = 13 + 12 = 25
Q.68
Hard
A person deposits Rs. 5000 in a bank at 6% per annum for 3 years at compound interest. What is the compound interest earned?
A
Rs. 935.46
B
Rs. 955.08
C
Rs. 965.44
D
Rs. 975.20
Correct Answer:
B. Rs. 955.08
Explanation:
Amount = 5000(1.06)³ = 5000 × 1.191016 = 5955.08. CI = 5955.08 - 5000 = 955.08
Q.69
Hard
A and B together can do a work in 12 days. B and C together can do it in 15 days. A and C together can do it in 20 days. How long will A alone take to complete the work?
A
28 days
B
30 days
C
32 days
D
35 days
Correct Answer:
B. 30 days
Explanation:
A+B = 1/12, B+C = 1/15, A+C = 1/20. Adding all: 2(A+B+C) = 1/12 + 1/15 + 1/20 = 5/60 + 4/60 + 3/60 = 12/60 = 1/5. So A+B+C = 1/10. A = (A+B+C) - (B+C) = 1/10 - 1/15 = 3/30 - 2/30 = 1/30. A alone takes 30 days
Q.70
Hard
A vessel contains 80 liters of milk. From this, 8 liters is removed and replaced with water. This process is repeated two more times. What is the quantity of milk left in the vessel?
A
58.32 liters
B
60 liters
C
58.6 liters
D
59.04 liters
Correct Answer:
A. 58.32 liters
Explanation:
After each operation, milk remaining = 80 × (1 - 8/80) = 80 × 0.9. After 3 operations: 80 × (0.9)³ = 80 × 0.729 = 58.32 liters
