Central Exam — Quantitative Aptitude
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Showing 681–690 of 1,106 questions
Q.681
Easy
Numbers
A man invests Rs. 8000 at 12% p.a. simple interest for 18 months. What amount does he receive?
Correct Answer:
A. Rs. 9440
Explanation:
SI = (8000 × 12 × 1.5)/100 = 1440. Amount = 8000 + 1440 = Rs. 9440
Q.682
Easy
Numbers
Pipe A fills a tank in 24 minutes, Pipe B in 36 minutes. If both work together, how long to fill the tank?
Correct Answer:
B. 14.4 minutes
Explanation:
Combined rate = 1/24 + 1/36 = (3+2)/72 = 5/72. Time = 72/5 = 14.4 minutes
Q.683
Easy
Numbers
A train travels at 72 km/h. How many metres does it cover in 25 seconds?
Correct Answer:
B. 500 m
Explanation:
Speed in m/s = 72 × 5/18 = 20 m/s. Distance = 20 × 25 = 500 m
Q.684
Easy
Numbers
A boat's speed in still water is 15 km/h. Stream speed is 3 km/h. What is the ratio of downstream to upstream speed?
Correct Answer:
B. 3:2
Explanation:
Downstream = 15 + 3 = 18. Upstream = 15 - 3 = 12. Ratio = 18:12 = 3:2
Q.685
Easy
Numbers
Cost price of an article is Rs. 500. It is sold at 24% profit. What is selling price?
Correct Answer:
C. Rs. 624
Explanation:
SP = 500 × 1.24 = Rs. 620. Wait, let me recalculate: 500 + (500 × 0.24) = 500 + 120 = 620. Correct answer should be B.
Q.686
Medium
Numbers
A sum becomes Rs. 1,331 in 3 years at 10% p.a. compound interest. What is principal?
Correct Answer:
A. Rs. 1000
Explanation:
A = P(1.1)³ = 1.331P. Given A = 1331, so P = 1000
Q.687
Medium
Numbers
Workers A and B together complete a job in 12 days. A alone takes 20 days. How many days for B alone?
Correct Answer:
C. 30 days
Explanation:
B's rate = 1/12 - 1/20 = (5-3)/60 = 2/60 = 1/30. B takes 30 days
Q.688
Medium
Numbers
Marked price is Rs. 800. After successive discounts of 10% and 15%, what is final selling price?
Correct Answer:
B. Rs. 612
Explanation:
After 10% discount: 800 × 0.9 = 720. After 15% discount: 720 × 0.85 = 612
Q.689
Medium
Numbers
A man covers 120 km in 8 hours partly by train at 20 km/h and partly by bus at 12 km/h. Distance by train?
Correct Answer:
B. 60 km
Explanation:
Let train distance = x. Then x/20 + (120-x)/12 = 8. Solving: 3x + 5(120-x) = 480. x = 60
Q.690
Medium
Numbers
Three pipes A, B, C can fill a tank in 20, 30, 60 minutes respectively. Time to fill if all three work together?
Correct Answer:
C. 10 minutes
Explanation:
Combined rate = 1/20 + 1/30 + 1/60 = (3+2+1)/60 = 6/60 = 1/10. Time = 10 minutes