Problem Solving

BTGmoderatorDC wrote: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

OA C

Source: Magoosh

Distance = 350 miles
Average speed = 50 mph

Time taken = Distance/Speed

Total time taken = 350/50 = 7 hrs

The correct answer: C

Hope this helps!

-Jay
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BTGmoderatorDC wrote: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

OA C

Source: Magoosh

As the others have shown, the fast approach is to recognize that: travel time = distance/speed = 350/50 = 7 hours

However, we could also (if necessary) solve this by applying some 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

BTGmoderatorDC wrote: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

We can use the formula:

Average = total distance/total time

50 = 350/t

50t = 350

t = 7 hours

Answer: C