Ok, to start of if 4 tomatoes cost $14, that means 2 tomatoes cost $7. This probably means 1 tomato cost $3.50 and 3 tomatoes cost $10.50. Hope this helps!
This could be wrong but the remaining pieces he can cut is 3 because if you divide 400 with 8 , it’s 35 as the answer, so then subtract 35 with 15 till you can subtract 15 from it