3. Two friends left school at the same time and drove in opposite directions. One friend averages 40 miles per hour, and the other friend averages 35 miles per hour. When will they be 150 miles apart?

A. 2.875 hr
B. 2.000 hr
C. 2.140 hr
D. 1.875 hr



Answer :

To solve this problem, we need to determine the time when the two friends will be 150 miles apart, given their respective speeds and that they are traveling in opposite directions.

1. Identify the speeds of the friends:
- Speed of the first friend: 40 miles per hour
- Speed of the second friend: 35 miles per hour

2. Calculate their combined speed when traveling in opposite directions:
- When two objects move in opposite directions, their speeds add up.
- Combined speed = Speed of first friend + Speed of second friend
- Combined speed = 40 miles per hour + 35 miles per hour
- Combined speed = 75 miles per hour

3. Use the formula for distance:
- Distance = Speed × Time

4. Given the total distance apart:
- Distance = 150 miles

5. Solve for time:
- Time = Distance / Combined speed
- Time = 150 miles / 75 miles per hour

6. Calculate the time:
- Time = 2 hours

So, the correct answer is that the two friends will be 150 miles apart after 2 hours.

Therefore, the correct choice is:
о 2.000 hr