Asked by Sam

A van travels for 3 hours at an average speed of 40 mph. How much longer must the van travel at an average of 55 mph so that the average speed for the entire trip will be 50 mph?
Answered by Mia
6 hours
Answered by Sam
Can you explain how you got that please?
Answered by Henry
d1 = V1*T1 = 40 * 3 = 120 mi.

d2 = V2*T2 = 55 * T2 = 55T2.

Vavg. = (d1+d2)/(T1+T2) = 50 mi/h.
(120+55T2)/(3+T2) = 50.
120 + 55T2 = 150 + 50T2.
5T2 = 30.
T2 = 6 Hours.

There are no AI answers yet. The ability to request AI answers is coming soon!