Question

Christy went on a round-trip bicycle ride starting at her house. When she left, she traveled downhill at a rate of 24 kilometers per hour (kph). She rested for 30 minutes, and then returned to her house. Since the return trip was partly uphill, it took half an hour longer and Christy averaged only 20 kph. How long did the return trip take?

Answer 1

Answer:

It took 3 hours to return home.

Step-by-step explanation:

• 1 hour for travelling downhill.
• 30 minutes rest.
• 1 hour and 30 minutes for travelling uphill.
• Total time taken = 1 hour + 30 minutes + 1 hour and 30 minutes = 3 hours total.

Answer 2

Answer:

The return trip took 3 hours.

Step-by-step explanation:

Suppose, the time required to travel downhill is  $t$ hours.

Since the return trip was partly uphill, it took half an hour longer. So, the time required for the return trip will be:  $(t+0.5)$ hours.

Given that, the speed for travelling downhill was 24 kph and the speed for travelling uphill was 20 kph.

We know that,  $Distance= speed*time$

As, the distances traveled in both trips are equal, so the equation will be........

$24t=20(t+0.5)\\ \\ 24t=20t+10\\ \\ 4t=10\\ \\ t=\frac{10}{4}= 2.5$

So, the time required for the return trip will be:  $(2.5+0.5)= 3$ hours.