A kangaroo jumps along a straight line. Pushing off with its left foot, it jumps 3 meters, with its right foot - 5 meters, and with both feet - 7 meters.

How can it cover exactly 200 meters in 30 jumps?
If all 30 jumps are 7 m, then the kangaroo will cover 10 m more than needed. Replacing a 7 m jump with a 5 m jump reduces this distance by 2 m, and replacing it with a 3 m jump reduces it by 4 m. The number 10 can be represented as the sum of twos and fours in three ways: $2+2+2+2+2$, $2+2+2+4$, and $2+4+4+4$. Hence, the first three answers.

A 7 (5) m jump backward reduces the distance by 14 (12) m, which is too much. However, a 3 m jump backward reduces the distance by exactly 10 m. Hence, the last answer.

## Answer

You can make 25 jumps of 7 m and 5 jumps of 3 m, or 26 jumps of 7 m, three jumps of 5 m, and one jump of 3 m, or 27 jumps of 7 m, one jump of 5 m, and two jumps of 3 m, or 29 jumps of 7 m and one jump of 3 m backward.