Q. 41
Which of these pipes will empty a pool the fastest?
1. One pipe of diameter 60 cm
2. Two pipes of diameter 30 cm each
3. Three pipes of diameter 20 cm each
(A) 1
(B) 2
(C) 3
(D) None of these
Answer: (A) 1
Explanation: N/A
Q. 42
A tank has a leak which would empty the completely filled tank in 10 hours. If the tank is full of water and a tap is opened which admits 4 litres of water per minute in the tank, the leak takes 15 hours to empty the tank. How many litres of water does the tank hold?
(A) 2400 litres
(B) 4500 litres
(C) 1200 litres
(D) 7200 litres
Answer: (D) 7200 litres
Explanation: The capacity of tank = x litre (suppose)
Quantity of water emptied by the leak = (x/10) litres
Quantity of water admitted to the tank = (4 * 60) = 240 litre/hour
According to the question, (x/10) -(x/15) = 240
Therefore, x = 7200 litres
Q. 43
Three taps A, B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternatively. The tank will be full in
(A) 6 hours
(B) 6(1/2) hours
(C) 7 hours
(D) 7(1/2) hours
Answer: (C) 7 hours
Explanation: N/A
Q. 44
Having the same capacity 9 taps fill up a water tank in 20 minutes. How many taps of the same capacity are required to fill up the same water tank in 15 minutes?
(A) 10
(B) 12
(C) 15
(D) 18
Answer: (B) 12
Explanation: N/A