Question 176527: A truck driver drove for 2 days. On the second day he drove for 3 hours longer and at an average speed of 15 miles per hour faster than he drove on the first day. If he drove a total of 1020 miles and spent 21 hours on the road driviing during the 2 days, what was his average speed on the first day, in miles per hour?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! A truck driver drove for 2 days. On the second day he drove for 3 hours longer
and at an average speed of 15 miles per hour faster than he drove on the first
day. If he drove a total of 1020 miles and spent 21 hours on the road driving
during the 2 days, what was his average speed on the first day, in miles per hour?
;
let s = av speed on the 1st day
then
(s+15) = av speed on the 2nd day
;
let t = drive time on the 1st day
then
(t+3) = drive time on the 2nd day
;
find t using the total hrs
day1 + day 2 = 21
t + (t+3) = 21
2t = 21 - 3
2t = 18
t = 9 hrs on the 1st day and 12 hrs on the 2nd day then
:
The total distance equation
9t + 12(t+15) = 1020
;
you should be able to do this now
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