Question

3 taps a, b & c fill a tank in 12, 15 & 20 hrs resp. If a is open all the time & b and c are open for one-hour each alternately, the tank will be full in how many hrs?

Answer 1

Answer:

Step-by-step explanation:

Taking the lcm(12,15,20) = 60 liters (capacity of the tank)

In 1 hr : A can fill 5 liters(60/12), B = 4 liters C = 3 liters

Its given that A is open all time and B & C alternately.

So in 1st hr : A+B = 9 liters

2nd hr : A+C = 8 liters

3rd hr : A+B = 9 liters

4th hr : A+C = 8 liters

5th hr : A+B = 9 liters

6th hr : A+C = 8 liters

7th hr : A+B = 9 liters

Total = 60 liters (Capacity of the tank).

So Ans = C. 7 hours.

Hope it helps you....