If the reservoir is 190 metres above the intake, how many cubic metres of water will there be delivered during the night?

This looks like a part of a full question. We need to know the acceleration due to gravity, water density, the power of the water or speed at which it flows to the reservoir. We also need to know the diameter of the pipe, the number of hours we are considering in this question because you mentioned the it will be delivered at night.

The answer would be: b

If you need an equation, it would be y=2x+8, y would be how long it grew, x being weeks.if you need how long he was asleep, it would be 4 weeks if he started with no beard, the equation would be x=8÷2if he did have a beard before hand, the equation would be 2w+x=8