SOLUTION: Mary starts jogging from her home to the park at the speed of 4kph. Half an hr later, Fred follows running at a speed of 9 kph. How long before Fred overtakes Mary?

Question 380164: Mary starts jogging from her home to the park at the speed of 4kph. Half an hr later, Fred follows running at a speed of 9 kph. How long before Fred overtakes Mary?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
Mary starts jogging from her home to the park at the speed of 4kph.
Half an hr later, Fred follows running at a speed of 9 kph.
How long before Fred overtakes Mary?
:
Let t = time required for F to catch M
:
When this happens, they will have traveled the same distance
:
convert 30 min to .5 hrs
:
Write a distance equation; dist = speed * time
;
F's dist = M's dist
9t = 4(t+.5)
9t = 4t + 2
9t - 4t = 2
5t = 2
t = hr for F to catch M
or
.4 * 60 = 24 minutes
:
:
Check solution by finding the dist each traveled, should be equal:
9 * .4 = 3.6 mi
4 *(.4 + .5) = 3.6 mi; confirms our solution of t = .4

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