Question

Sergio plans to drive 150 miles at a rate of 60 miles per hour. He figures that it will take 25 hours. Which is NOT a reason why this conclusion is wrong?

A. If he's driving more than 60 miles, the drive would take longer than 1 hour.
B. He should have multiplied 150 by 60 instead of dividing.
C. When you divide 60 by 150, you get 25 but the unit is not hours.
D. In 25 of an hour, he would drive less than 60 miles.

Answer 1

B. He should have multiplied 150 by 60 instead of dividing.

Explanation:

Speed = distance/time

Distance/time = speed

150/time = 60

time = 150/60

(Divide, not multiply)

time = 5/2

Answer 2

B

Explanation:

This is a distance-rate-time problem, so we need to use the equation:
`d=rt`, where d is the distance, r is the rate, and t is the time.

Here, we know that the total distance is 150, so d = 150. Also, we are given that Sergio's rate is 60 mph, so r = 60. Put these in:

d = rt

150 = 60t

To solve for t, we divide both sides by 60. Because we are dividing and not multiplying, we know that B is the only one that is incorrect.

Hope this helps!