Harry's trainer recommends Harry drink
8*(8 oz) = 64 oz
of water per day.
A pint is 16 oz, so this amounts to
(64 oz)*(1 pt)/(16 oz) = 4 pt
of water per day.
By drinking 3 full bottles of water, Harry drank
3*(1 1/4 pt) = 3 3/4 pt
of water.
This amount of water (3 3/4 pt) is less than the 4 pt recommended by the trainer. Harry's claim that he drank the full amount is not true.