Question

The top running speed of a cheetah is double the top running speed of a jackal. The top running speed of an elk is 9 miles per hour faster than that of a jackal. If each of these three animals could run at top speed for an hour​ (which, of​ course, is not​ possible), they could run a combined distance of 133 miles. What is the top running speed of each of these three​ animals?

Answer 1

Cheetah: 62 miles per hour.

Elk: 40 miles per hour.

Jackal: 31 miles per hour.

Explanation:

Let be "c" the top running speed of the cheetah, "j" the the top running speed of the jackal and "e" the top running speed of the elk.

Based on the exercise, we know that:

`c=2j\\\\e=j+9`

Since they they could run a combined distance of 133 miles in an hour, we can write the following expression:

`c+j+e=133`

Substituting
`c=2j` and
`e=j+9` into the expression and solving for "j", we get:

`2j+j+j+9=133\\\\4j=133-9\\\\j=(124)/(4)\\\\j=31`

Finally, we must substitute the value of "j" into
`c=2j` and
`e=j+9`. Then:

`c=2(31)=62`

`e=31+9=40`