SOLUTION: A truck driver traveled at 40 mph for the first part of a 646-mile trip, then increased his speed to 58 mph for the rest of the trip. The entire trip took 13 hours. How many ho
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Question 334865: A truck driver traveled at 40 mph for the first part of a 646-mile trip, then increased his speed to 58 mph for the rest of the trip. The entire trip took 13 hours. How many hours are traveled at 58 mph? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! A truck driver traveled at 40 mph for the first part of a 646-mile trip,
then increased his speed to 58 mph for the rest of the trip.
The entire trip took 13 hours. How many hours are traveled at 58 mph?
:
let t = time traveled at 58 mph
then
(13-t) = time at 40 mph
:
Write a distance equation; dist = speed * time
;
40 mph dist + 58 mph dist = 646 mi
40(13-t) + 58t = 646
:
520 - 40t + 58t = 646
-40t + 58t = 646 - 520
18t = 126
t =
t = 7 hrs at 58 mph
;
:
Check solution by finding the distances
13 - 7 = 6 hrs at 40 mph
40*6 + 58*7 =
240 + 406 = 646
