Question

A student is running a 5-kilometer race. He runs 1 kilometer every 3 minutes. Select the function that describes his distance from the finish line after x minutes.
f(x) = − 1 over 3 x + 5
f(x) = − 1 over 5 x + 3
f(x) = 1 over 5 x + 5
f(x) = 1 over 3 x + 3

Answer 1

-1/5x+3 because u have ran -1 out of 5 kilometers

Answer 2

Answer:  The correct option is

(D) $f(x)=\dfrac{1}{3}x+5.$

Step-by-step explanation:  Given that a student is running a 5-kilometer race. He runs 1 kilometer every 3 minutes.

We are to select the function that describes his distance from the finish line after x minutes.

When the student reaches the finish line, he already covered a distance of 5 kilometers.

Now, in 3 minutes, distance covered by the student = 1 kilometer.

So, in 1 minute, distance covered by the student is given by

$\dfrac{1}{3}~\textup{kilometer}.$

Therefore, in x minutes, the distance covered by the student is

$\dfrac{1}{3}x~\textup{kilometer}.$

That is, the total distance from the finish line after x minutes is given by

$f(x)=\dfrac{1}{3}x+5.$

Thus, option (D) is CORRECT.