Question 681525
two cars started a journey from A to B 150 km apart on the same road towards each other.
 The car from A traveled at a constant speed of 10knn/h more then that of the other car that also traveled at a constant speed.
 the two cars crossed each other after 72 mins.
 what was the speed of the car that started from b.
:

Let s = Car from A speed
then
(s-10) = Car from B speed
:
Change 72 min to 1.2 hrs
:
Write a distance equation; dist = time * speed
Car A dist + Car B dist = 150 km
1.2s + 1.2(s-10) = 150
1.2s + 1.2s - 12 = 150
2.4s = 150 + 12
s = 162/2.4
s = 67.5 km/hr car A
then
57.5 km/hr car B
:
:
See if that checks out, find the dist each traveled
1.2(67.5) = 81 km
1.2(57.5) = 69 km
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total dist: 150 km