You can put this solution on YOUR website! If a car travels at 70mph and then 50mph for a total of 320miles in 5 hours, how many hours did it travel at each speed?
:
Just think this through
:
Let t = time at 70 mph
then
(5-t) = has to be the time at 50 mph, right?
:
Write a simple distance equation (dist = speed * time)
:
Dist at 70 + dist at 50 = 320 mi
70t + 50(5-t) = 320
:
70t + 250 - 50t = 320
:
70t - 50t = 320 - 250
:
20t = 70
t =
t = 3.5 hrs at 70 mph
then
5 - 3.5 = 1.5 hrs at 50
;
;
Prove this by finding the total dist
70(3.5) + 50(1.5)
245 + 75 = 320 mi
