Question

Ms.Lieber takes 4 hours to drive 210 miles from her home to Yosemite national park. If ms.Lieber's avarege sleed for the first two hours is 60 miles per hour, find her avarage sleed for the last two hours

Answer 1

45 miles per hour.

Explanation:

We have been given that Ms. Lieber takes 4 hours to drive 210 miles from her home to Yosemite national park. Ms. Lieber's average speed for the first two hours is 60 miles per hour.

Let us find distance traveled by Ms. Lieber in 2 hours.

`\text{Distance}=\text{Speed*Time}`

`\text{Distance traveled by Ms. Lieber in 2 hours}=60\frac{\text{miles}}{\text{ hour}}* 2\text{ hours}`

`\text{Distance traveled by Ms. Lieber in 2 hours}=60* 2\text{ miles}`

`\text{Distance traveled by Ms. Lieber in 2 hours}=120\text{ miles}`

`\text{Remaining distance}=(210-120)\text{ miles}`

`\text{Remaining distance}=90\text{ miles}`

`\text{Speed}=\frac{\text{Distance}}{\text{Time}}`

`\text{Ms. Lieber's average speed for last 2 hours}=\frac{90\text{ miles}}{2\text{hour}}`

`\text{Ms. Lieber's average speed for last 2 hours}=45\frac{\text{ miles}}{\text{hour}}`

Therefore, Ms. Lieber's average speed for the last 2 hours was 45 miles per hour.