Together, the pipes release 3300 in 10 min, so the rate is 330 L/min.

Rough estimate: The amount coming out of the 2 pipes is about 300 L/min so if each pipe has the same width, then the rate will be about 150 L/min for each pipe. But one pipe's rate is 50 L/min more than the other, so we expect the answers to be around 125 L/min and 175 L/min.

Solution: Let x be the rate of the slower pipe (in L/min).

The rate of the faster pipe will be

(x + 50) L/min.

Together they release: x + (x + 50) = 330

So 2x + 50 = 330

2x = 280

x = 140

So the drainage rates of the 2 pipes are 140 L/min and 190 L/min.

[This is close to our earlier estimate. Together they give a rate of 330 L/min and they differ by 50 L/min, so we can be confident our answer is correct.]