Kangaroos jump 4 1/2=4.5 meters each time, rabbits jump 2 3/4=2.75 meters each time, and there is a balloon every 99/8= 12.375 meters.

Kangaroo: 12.375÷4.5=2.75 times

2.75 degrees is not an integer, and the least square is 4 2.75×4= 1 1 degree.

The kangaroo jumped 4.5× 1 1=49.5 (m) when stepping on a balloon for the first time.

Rabbit: 12.375÷2.75=4.5 times

4.5 times is not an integer, and the least square is 2. 4.5×2=9 times.

The rabbit jumped 2.75×9=24.75 meters before stepping on the balloon for the first time.

So the rabbit stepped on the balloon first, and then the kangaroo jumped 4.5×9=40.5 meters.