CPM Homework Help : PC Problem 10-91

Multiple Choice: Excluding breaks, it took Chun a total of $10$ hours to bike to a cousin’s home and return. On the way, Chun biked alone and averaged $15$ mph. On the way back, with his cousin, he averaged $10$ mph. How many miles was it to his cousin’s home?

$50$

$100$

$60$

$40$

$120$

Hint:

If it took Chun $t$ hours to get there, write an expression for the hours it took him to get back.

Answer:

$10 − t$

Hint:

distance there = distance back
$\left(\text{rate}_{1}\right)\left(\text{time}_{1}\right) = \left(\text{rate}_{2}\right)\left(\text{time}_{2}\right)$

When you solve your equation you will get an answer for $t$ .
Make sure you answer the question being asked!