The first pipe runs 5 liters of water per minute less than the second pipe. How many liters of water per

The first pipe runs 5 liters of water per minute less than the second pipe. How many liters of water per minute does the second pipe let through, if it fills a tank with a volume of 400 liters in 2 hours 20 minutes faster than the first pipe fills a tank with a volume of 900 liters?

Let us denote by x the number of liters that the first pipe passes per minute. Then we translate 2 hours 20 minutes into minutes, we get 140 minutes. Let’s compose and solve the equation:

400 / x + 140 = 900 / (x + 5).

400x + 140x (x + 5) = 900 (x + 5).

140x ^ 2 + 200x – 4500 = 0.

7x ^ 2 + 10x -225 = 0.

x = 5.

Consequently, the first pipe flows 5 liters per minute. Then the second passes 5 liters more, hence 10 liters.

Answer: 10 liters.