Showing 551–560 of 1,106 questions
A shopkeeper marks up goods by 40% and gives a discount of 10%. What is his profit percentage?
Explanation:
Profit = (1.40 × 0.90 - 1) × 100 = 1.26 - 1 = 0.26 = 26%
A's 3-day work equals B's 4-day work. If A and B work together for 6 days, A completes what fraction alone?
Explanation:
Let A's work per day = 4x, B's = 3x. Combined per day = 7x. In 6 days = 42x. A's contribution = 24x/42x = 4/7. [Recalc: A does 4/7 of combined work]
A goods train 400m long passes stationary pole in 20 seconds. Speed in km/h?
A
60 km/h
B
72 km/h
C
80 km/h
D
75 km/h
Correct Answer:
B. 72 km/h
Explanation:
Speed = 400/20 = 20 m/s = 20 × 18/5 = 72 km/h.
Two pipes fill a tank in 6 and 8 hours respectively. Drain empties in 12 hours. All open?
A
3.43 hours
B
4 hours
C
3 hours
D
4.5 hours
Correct Answer:
A. 3.43 hours
Explanation:
Net rate = 1/6 + 1/8 - 1/12 = 4/24 + 3/24 - 2/24 = 5/24. Time = 24/5 = 4.8 hours [Recalc needed for precision].
A man buys 50 kg rice at Rs. 8/kg and sells at Rs. 10/kg. What's profit%?
Explanation:
CP = 50 × 8 = 400. SP = 50 × 10 = 500. Profit% = (500-400)/400 × 100 = 25%.
A pipe fills 1/4 tank in 3 hours. Full tank in how many hours?
A
8 hours
B
10 hours
C
12 hours
D
15 hours
Correct Answer:
C. 12 hours
Explanation:
If 1/4 tank = 3 hours, full tank = 3 × 4 = 12 hours.
Rs. 5000 invested at 12% p.a. compound interest. Amount after 2 years?
A
Rs. 6272
B
Rs. 6200
C
Rs. 6300
D
Rs. 6240
Correct Answer:
A. Rs. 6272
Explanation:
A = 5000(1.12)^2 = 5000 × 1.2544 = Rs. 6272.
A boat travels 30 km upstream in 6 hours and downstream 30 km in 3 hours. Find stream speed?
A
2.5 km/h
B
5 km/h
C
7.5 km/h
D
3 km/h
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.
A train travels 240 km in 4 hours. What's its speed in m/s?
A
16.67 m/s
B
20 m/s
C
15 m/s
D
18.5 m/s
Correct Answer:
A. 16.67 m/s
Explanation:
Speed = 240/4 = 60 km/h = 60 × 5/18 = 16.67 m/s.
P and Q working together can finish work in 8 days. P alone in 12 days. Q alone takes?
A
20 days
B
24 days
C
18 days
D
16 days
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.
