GMAT Practice Question: Jonah drove the first half of a 100 -mile trip in x hours and the second half in y...
Question
Jonah drove the first half of a 100 -mile trip in x hours and the second half in y hours. Which of the following is equal to Jonah's average speed, in miles per hour, for the entire trip?
- 50/x+y
- 100/x+y
- 25/x+25/y
- 50/x+50/y
- 100/x+100/y
Topics: word problems, rates, translations, units
Solution
Step 1
We translate "a 100-mile trip" into an equation for the total distance.
Total distance = 100
Step 2
We translate "in x hours and y hours" into an equation for the total time.
Total time = x + y
Step 3
We use the distance formula to find average speed by dividing total distance by total time.
Average speed = Total distanceTotal time = 100/x+y
Answer
100/x+y
