This question is not valid because the gift card is only 90 pounds. You states that the Coffee she bought was 553 dollars. This means she will have negative profit, therefore this question is not states correctly.
As it can be see that x ≥ 75 and Q is product of three consecutive terms (x-1), x, (x+1) which is always completely divisible by 2, 3 and 6. So remainder is zero
