You need to determine how many flies each catches in a day. To do that …

Little frog 3 x 17 = ???

3 flies an hour for 17 hours (24-7)

Bull frog 8 x 6 = ???

8 flies an hour for 6 hours (24-18)

Once you have those numbers, you can answer your questions.

Big Bull Frogs: 24 – 18 = 6 hours * 8 (per hr) = 48 * 3 (days) = 144

1. The Little green frog catches more flies.

2. It catches 9 more flies than the bull frog.

lgf = 3(17)=51 flies per day, over 3 days will catch 153 flies

BBf=8(24-18)

=8(6)=48 flies per day, over 3 days will catch 144 flies

lgf caught 9 more flies over 3 days.

LGF 3*(24-7) => 3*17 => 51 day 153

BBF 8*(24-18) =>8*6 => 48 day 144

2) LGF caught 9 more flies.