How many cartons of milk

Question

Mervin had  some cartons of milk. He sold 2/5 in morning and 3/4 of the remainder in the afternoon. 24 cartons of milk were sold in the afternoon than in the morning. How many cartons of milk did mervin have?

Answer 1

After selling 2/5 he would be left with 3/5 and 3/4 of this gives us 9/20 of the initial amount.

So, if x is the number of cartons he had at the start, then (9/20-2/5)x=24.

((9-8)/20)x=24, x/20=24, x=480.

CHECK

2/5 of 480=192 sold in the morning. That leaves 288 and 3/4 of this is 216 cartons, which is 24 more than he sold in the morning.