A fisherman catches thirty fish in a five-day fishing competition ..........How many fish did he catch on the first day?

Question

A fisherman catches thirty fish in a five-day fishing competition. Each day he catches three more than the last.

How many fish did he catch on the first day?

Answer 1

First day he didn't catch any fish = 0
Second day 0+3 = 3
3rd day 3+3 = 6
4th day 6+3 = 9
Last day 9+3 = 12

Total 0+3+6+9+12 = 30

Answer 2

total fishes caught if in the first day is x=5x+30=30
solving the value of x=0 ie the first day got no fish
ans=0