Question 513617
It took John 2 hours to bike from Dublin to Pickerington at a constant speed. The return trip took only 1.5 hours because he increased his speed by 6 mph. How far apart are Dublin and Pickerington?
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Let d = the distance from D to P
The speed of the outbound trip is:
s = d/2 [D -> P takes 2 h]
The speed of the return trip is:
s + 6 = d/1.5 [P -> D takes 1.5 h; speed increased 6 mph]
Substitute the value for s in the 1st equation into the 2nd equation:
d/2 + 6 = d/1.5
Solve for d:
(2d - 1.5d)/3 = 6
d = 36 mi