Showing 561–570 of 1,106 questions
A can do 1/3 of work in 5 days. How many days for complete work?
A
10 days
B
12 days
C
15 days
D
18 days
Correct Answer:
C. 15 days
Explanation:
If 1/3 work = 5 days, then full work = 5 × 3 = 15 days.
A's income is 25% more than B's. By what % is B's income less than A's?
Explanation:
Let B's income = 100, A's = 125. B's is less by 25/125 × 100 = 20%.
A trader marks goods 40% above cost price and gives 10% discount. What's his profit%?
Explanation:
Let CP = 100. MP = 140. SP = 140 × 0.9 = 126. Profit% = (126-100)/100 × 100 = 26%.
A sum becomes Rs. 3600 in 3 years at 10% p.a. compound interest. What's the principal?
A
Rs. 2500
B
Rs. 2703.67
C
Rs. 3000
D
Rs. 2840
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.
Simple Interest on Rs. 1000 for 2 years at 8% p.a. is?
A
Rs. 160
B
Rs. 166.40
C
Rs. 180
D
Rs. 200
Correct Answer:
A. Rs. 160
Explanation:
SI = (P × R × T)/100 = (1000 × 8 × 2)/100 = Rs. 160.
A boat's speed in still water is 15 km/h, stream speed 3 km/h. What's downstream speed?
A
12 km/h
B
18 km/h
C
15 km/h
D
5 km/h
Correct Answer:
B. 18 km/h
Explanation:
Downstream speed = boat speed + stream speed = 15 + 3 = 18 km/h.
Two trains 120m and 180m long run towards each other at 40 km/h and 50 km/h. Time to cross?
A
10.8 seconds
B
14.4 seconds
C
12 seconds
D
15.6 seconds
Correct Answer:
A. 10.8 seconds
Explanation:
Relative speed = 40 + 50 = 90 km/h = 25 m/s. Total distance = 120 + 180 = 300m. Time = 300/25 = 12 seconds. [Recalc: 12 seconds should match option C. Time = 300/25 = 12 seconds]
Pipe A fills a tank in 12 hours, Pipe B empties it in 18 hours. If both open together, how long to fill?
A
30 hours
B
36 hours
C
24 hours
D
40 hours
Correct Answer:
B. 36 hours
Explanation:
Net rate = 1/12 - 1/18 = 3/36 - 2/36 = 1/36. Time = 36 hours.
A can complete a work in 15 days, B in 20 days. How many days will they take working together?
A
6 days
B
8 days
C
8.57 days
D
7.5 days
Correct Answer:
C. 8.57 days
Explanation:
A's work rate = 1/15, B's rate = 1/20. Combined = 1/15 + 1/20 = 7/60. Time = 60/7 ≈ 8.57 days.
A shopkeeper sells an item at Rs. 480 with 20% profit. What is the cost price?
A
Rs. 350
B
Rs. 400
C
Rs. 360
D
Rs. 420
Correct Answer:
B. Rs. 400
Explanation:
SP = CP × (1 + profit%). 480 = CP × 1.2. CP = 480/1.2 = Rs. 400.
