Showing 411–420 of 500 questions
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A shopkeeper marks an item at Rs. 500. He gives a discount of 20% and still makes a profit of 25%. What is the cost price?
A
Rs. 320
B
Rs. 400
C
Rs. 350
D
Rs. 380
Correct Answer:
A. Rs. 320
Explanation:
Selling Price = 500 × 80/100 = Rs. 400. If profit is 25%, then CP = 400 × 100/125 = Rs. 320
Two pipes A and B can fill a tank in 12 hours and 15 hours respectively. If both pipes are opened together, in how many hours will the tank be filled?
A
6.67 hours
B
5.5 hours
C
7.5 hours
D
8 hours
Correct Answer:
A. 6.67 hours
Explanation:
Combined rate = 1/12 + 1/15 = 5/60 + 4/60 = 9/60 = 3/20. Time = 20/3 = 6.67 hours
A train 250m long crosses a platform 150m long in 20 seconds. What is the speed of the train?
A
54 km/h
B
72 km/h
C
45 km/h
D
60 km/h
Correct Answer:
B. 72 km/h
Explanation:
Distance covered = 250 + 150 = 400m. Speed = 400/20 = 20 m/s = 20 × 18/5 = 72 km/h
A boat's speed in still water is 12 km/h and the speed of current is 3 km/h. How long will it take to travel 60 km downstream?
A
4 hours
B
3.75 hours
C
5 hours
D
4.5 hours
Correct Answer:
A. 4 hours
Explanation:
Downstream speed = 12 + 3 = 15 km/h. Time = 60/15 = 4 hours
If a number is decreased by 40%, it becomes 300. What is the original number?
Explanation:
Let original number be x. x × 60/100 = 300. x = 300 × 100/60 = 500
A man buys goods for Rs. 2500 and sells them at a loss of 8%. What is the selling price?
A
Rs. 2300
B
Rs. 2200
C
Rs. 2400
D
Rs. 2100
Correct Answer:
A. Rs. 2300
Explanation:
Selling Price = 2500 × 92/100 = Rs. 2300
X and Y together can complete a work in 18 days. X alone can complete it in 30 days. In how many days can Y alone complete the work?
A
45 days
B
38 days
C
42 days
D
35 days
Correct Answer:
A. 45 days
Explanation:
Y's rate = 1/18 - 1/30 = 5/90 - 3/90 = 2/90 = 1/45. Y can complete in 45 days
Rs. 1000 is invested at 10% per annum compound interest for 2 years. What is the final amount?
A
Rs. 1210
B
Rs. 1200
C
Rs. 1100
D
Rs. 1320
Correct Answer:
A. Rs. 1210
Explanation:
Amount = 1000(1 + 10/100)² = 1000 × 1.1 × 1.1 = Rs. 1210
A boat goes 30 km upstream in 6 hours and 30 km downstream in 3 hours. What is the speed of the boat in still water?
A
7.5 km/h
B
6.5 km/h
C
8 km/h
D
5 km/h
Correct Answer:
A. 7.5 km/h
Explanation:
Upstream speed = 30/6 = 5 km/h. Downstream speed = 30/3 = 10 km/h. Boat speed = (5+10)/2 = 7.5 km/h
A product's price increased by 25%, then decreased by 20%. What is the net change?
A
0% (no change)
B
+5%
C
-5%
D
+10%
Explanation:
Let original price = 100. After 25% increase = 125. After 20% decrease = 125 × 80/100 = 100. Net = +5% gain
