Carcass wrote:
Due to rush hour traffic, it takes Marcus twice as long to drive home from work as it does for him to drive to work. When he drives to work, his average speed is 50 miles per hour. When he drives home from work, his average speed is 25 miles per hour. If he spends a total of three hours in his car driving to and from work, how long is Marcus's commute one-way?
A. 25 miles
B. 40 miles
C. 45 miles
D. 50 miles
E. 55 miles
Kudos for the right answer and explanation
Question part of the project GRE Quantitative Reasoning Daily Challenge - (2021) EDITIONGRE - Math BookSo, the TOTAL driving time =
3 hoursAnd it takes Marcus
twice as long to drive home from work as it does for him to drive to workWe might already see that Marcus' travel time TO work is 1 hour, and his travel time FROM work is 2 hours.
However, we can also use some algebra to reach that same conclusion:
Let t = travel time TO work
So, 2t = travel time FROM work (since it takes twice as long to drive home from work)
We can write: t + 2t =
3 hours
Combine: 3t =
3Solve: t = 1, which means the travel time TO work is 1 hour
So, to get TO work, Marcus drives 50 miles per hour for 1 hour
Distance = (speed)(time) = (50)(1) = 50 miles
Answer: D