Question

Two pipes running together can fill a tank in minutes. If one pipe takes 5 minutes more than the other to fill the tank separately, find the time in which each pipe would fill the tank separately.

Answer 1

Answer:

Let the faster pipe fill the tank in ‘a’ min

Slower pipe fills it in ‘a + 5’ min.

 

Given, the pipes running together can fill a tank in  = 100/9 minutes.

 

In 1 min, part of tank filled = 9/100

 

⇒ 100(a + a + 5) = 9(a2 + 5a)

⇒ 200a + 500 = 9a2 + 45a

⇒ 9a2 – 155a - 500 = 0

⇒ 9a2 – 180a + 25a - 500 = 0

⇒ 9a(a – 20) + 25(a – 20) = 0

⇒ (9a + 25)(a – 20) = 0

⇒ a = 20 mins

Slower pipe will fill it in 25 min