Question 1128849: Thaddeus and Ian start at the same location and drive in opposite directions, but leave at different times. When they are 275 miles apart, their combined travel time is 12 hours. If Thaddeus drives at a rate of 20 miles per hour and Ian drives at a rate of 25 miles per hour, how long had each been driving?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Thaddeus and Ian start at the same location and drive in opposite directions, but leave at different times.
When they are 275 miles apart, their combined travel time is 12 hours.
If Thaddeus drives at a rate of 20 miles per hour and Ian drives at a rate of 25 miles per hour,
how long had each been driving?
:
let t = Thad's travel time
their total is 12 hrs, therefore
(12-t) = Ian's travel time
:
Write a dist equation; dist = speed*time
20t + 25(12-t) = 275
20t + 300 - 25t = 275
20t - 25t = 275 - 300
-5t = -25
t = -25/-5
t = +5 hrs is Thad's travel time
then obviously
12-5 = 7 hrs is Ian's
:
;
Check, find the actual dist each traveled
20(5) = 100 mi
25(7) = 175 mi
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tot dist 275
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