Question 307830
Ann walks 5 km/hr and betty walks 4 km/hr. If they start walking toward each other from a distance of 36 km, how many hours will it take for them to meet.

let them meet at a distance x from Ann
The distance from betty when they meet = 36-x
.
time taken to walk to the point of meeting by Ann = x/5
time taken by betty to walk to the point of meeting = 36-x/ 4

These times are same 
x/5 = 36-x/4

4x=5(36-x)
4x=180-5x
9x = 180
x= 20 miles.

This is the distance traveled by Ann at 5 mph

So they meet after 20 / 5 = 4 hours