vinay1983 wrote:One hour after Yolanda started walking from X to Y, a distance of 45 miles, Bob started walking along the same road from Y to X. If Yolanda's walking rate was three miles per hour and Bob's was four miles per hour, how many miles had Bob walked when they met?

1) 24
2) 23
3) 22
4) 21
5) 19.5

GMATGuruNY wrote:

vinay1983 wrote:One hour after Yolanda started walking from X to Y, a distance of 45 miles, Bob started walking along the same road from Y to X. If Yolanda's walking rate was three miles per hour and Bob's was four miles per hour, how many miles had Bob walked when they met?

1) 24
2) 23
3) 22
4) 21
5) 19.5

In the first hour, the distance traveled by Yolanda alone = 3 miles.
Remaining distance between Bob and Yolanda = 45-3 = 42 miles.

Bob's rate : Yolanda's rate = 4:3.
Implication:
When Bob and Yolanda travel toward each other, of every 7 miles, Bob travels 4 miles, while Yolanda travels 3 miles.
Thus, Bob will travel 4/7 of the remaining 42 miles:
(4/7) * 42 = 24.

The correct answer is A.

Side note:
Don't either of them own a car?