Question

You are going on a road trip!

You drive to your best friend's house and then get on the highway.
After 2.5 hours, you had traveled a total of 135 miles.
You can average 50 miles per hour after you leave your friend's house.

Answer 1

The answer is A.

Explanation:

Answer 2

Answer with explanation:

Total Distance traveled in 2.5 hours = 135 miles

Average speed for the total trip

`=\frac{135 \text{miles}}{2.5\text{hours}}\\\\=54 (miles)/(hour)`

Let time taken by person while going from his house to his friend house = t hours

Average Speed of person after leaving the friend's house. = 50 miles/hour

Let average speed of person while going from his house to his friend house =v miles/hour.

`\rightarrow 54=(50+v)/(2)\\\\ 108 -50=v\\\\v=58 (miles)/(hour)`

Also, Distance = Speed × Time

→135 = 58 × t +50 × (2.5 -t)

→135 = 58 t +125 - 50 t

→135 - 125 =8 t

→ 10 = 8 t

`t=(10)/(8)* \text{hours}=75\text{Minutes}`

So, i traveled at a speed of 58 miles /hour, for 75 minutes ,from my house to my friend's House in the entire trip.