Question

Jack and Jim went biking. Jack biked for 5 1/3 hours with average speed 12 1/2 miles per hour. Jim traveled exactly 1 1/5 as far as Jack did. How long was Jim’s trip?

Answer 1

Given that Jack biked for $5 \frac{1}{3}$ hours with an average speed of  $12 \frac{1}{2}$ miles per hour.

The distance travelled by Jack is given by

$d=speed\times time \\ \\ =12 \frac{1}{2}\times5 \frac{1}{3}= \frac{25}{2} \times \frac{16}{3} \\ \\ = \frac{200}{3} =66 \frac{2}{3} \ miles$

Given that Jim travelled exactly $1 \frac{1}{5}$ as far as Jack did, then the distance Jim travelled is given by

$d=1 \frac{1}{5} \times66 \frac{2}{3} \\ \\ = \frac{6}{5} \times \frac{200}{3} =80$

Therefore, the length of Jim's journey is 80 miles.