swerve wrote: ↑

Tue Mar 31, 2020 10:20 am

Bob drives at an average rate of 50 mph from Berkeley to Los Angeles, a distance of 350 miles. How long does it take him to complete the trip?

A. 4 hrs
B. 5 hrs
C. 7 hrs
D. 10 hrs
E. 12 hrs

The OA is C

Source: Magoosh

APPROACH #1: Formula
travel time = distance/speed = 350/50 = 7 hours
Answer: C


APPROACH #2: common sense
Bob's speed is 50 miles per hour.
In other words, for every 1 hour that elapses, Bob travels 50 miles

So, after 1 hour of traveling, Bob has traveled 50 miles
After 2 hours of traveling, Bob has traveled 100 miles
After 3 hours of traveling, Bob has traveled 150 miles
After 4 hours of traveling, Bob has traveled 200 miles
After 5 hours of traveling, Bob has traveled 250 miles
After 6 hours of traveling, Bob has traveled 300 miles
After 7 hours of traveling, Bob has traveled 350 miles
Answer: C

Cheers,
Brent

swerve wrote: ↑

Tue Mar 31, 2020 10:20 am

Bob drives at an average rate of 50 mph from Berkeley to Los Angeles, a distance of 350 miles. How long does it take him to complete the trip?

A. 4 hrs
B. 5 hrs
C. 7 hrs
D. 10 hrs
E. 12 hrs

The OA is C

Source: Magoosh

We can use the formula:

Average = total distance/total time

50 = 350/t

50t = 350

t = 7 hours

Answer: C