Question 453513: a car travels from A to B, a distance of 210 miles at 30 mph.Another car travels from B to A one hour afterwards with speed of 70 mph.A what point they cross.if the first car left at 10:00 hours, what is the time of their crossing.
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! A car travels from A to B, a distance of 210 miles at 30 mph.
Another car travels from B to A one hour after-wards, with speed of 70 mph.
At what point they cross, if the first car left at 10:00 hours?
What is the time of their crossing?
:
Summarize:
Car 1: A to B, 210 mi, 30 mph, left at 10:00
Car 2: B to A, 210 mi, 70 mph, left at 11:00
:
Let t = A's travel time when they meet
then
(t-1) = B's travel time when they meet
:
Write a distance equation, Dist = speed * time
Car 1 dist + Car 2 dist = 210 mi
30t + 70(t-1) = 210
30t + 70t - 70 = 210
100t = 210 + 70
100t = 280
t = 
t = 2.8 hrs, travel time of car 1 (left at 10 am)
Convert hrs min: 2 + .8(60) 2 hrs 48 min
10:00 + 2:48 = 12:48 PM when they meet
:
Find the distance from A when they meet:
30 * 2.8 = 84 mi from A
Check this by finding the dist from B, using Car 2
70 * 1.8 = 126 mi from B
Check this find the total: 84 + 126 = 210 mi
:
Summarize, Car 1 meets Car 2, 84 mi from town A at 12:48 PM
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