Central Exam — Quantitative Aptitude
UPSC · SSC · Bank · Railway · NDA — Central Government Exam MCQ Practice
Showing 541–550 of 1,106 questions
Q.541
Easy
Numbers
A boat's speed in still water is 15 km/h, stream speed 3 km/h. What's downstream speed?
Correct Answer:
B. 18 km/h
Explanation:
Downstream speed = boat speed + stream speed = 15 + 3 = 18 km/h.
Q.542
Easy
Numbers
Simple Interest on Rs. 1000 for 2 years at 8% p.a. is?
Correct Answer:
A. Rs. 160
Explanation:
SI = (P × R × T)/100 = (1000 × 8 × 2)/100 = Rs. 160.
Q.543
Medium
Numbers
A sum becomes Rs. 3600 in 3 years at 10% p.a. compound interest. What's the principal?
Correct Answer:
B. Rs. 2703.67
Explanation:
A = P(1 + R/100)^T. 3600 = P(1.1)^3 = P(1.331). P = 3600/1.331 ≈ Rs. 2703.67.
Q.544
Medium
Numbers
A trader marks goods 40% above cost price and gives 10% discount. What's his profit%?
Correct Answer:
A. 26%
Explanation:
Let CP = 100. MP = 140. SP = 140 × 0.9 = 126. Profit% = (126-100)/100 × 100 = 26%.
Q.545
Medium
Numbers
A's income is 25% more than B's. By what % is B's income less than A's?
Correct Answer:
A. 20%
Explanation:
Let B's income = 100, A's = 125. B's is less by 25/125 × 100 = 20%.
Q.546
Medium
Numbers
A can do 1/3 of work in 5 days. How many days for complete work?
Correct Answer:
C. 15 days
Explanation:
If 1/3 work = 5 days, then full work = 5 × 3 = 15 days.
Q.547
Medium
Numbers
P and Q working together can finish work in 8 days. P alone in 12 days. Q alone takes?
Correct Answer:
B. 24 days
Explanation:
Combined rate = 1/8. P's rate = 1/12. Q's rate = 1/8 - 1/12 = 1/24. Q takes 24 days.
Q.548
Medium
Numbers
A train travels 240 km in 4 hours. What's its speed in m/s?
Correct Answer:
A. 16.67 m/s
Explanation:
Speed = 240/4 = 60 km/h = 60 × 5/18 = 16.67 m/s.
Q.549
Medium
Numbers
A boat travels 30 km upstream in 6 hours and downstream 30 km in 3 hours. Find stream speed?
Correct Answer:
A. 2.5 km/h
Explanation:
Upstream speed = 30/6 = 5 km/h. Downstream = 30/3 = 10 km/h. Stream speed = (10-5)/2 = 2.5 km/h.
Q.550
Medium
Numbers
Rs. 5000 invested at 12% p.a. compound interest. Amount after 2 years?
Correct Answer:
A. Rs. 6272
Explanation:
A = 5000(1.12)^2 = 5000 × 1.2544 = Rs. 6272.