SOLUTION: If you must average 60 km/h for a 90-km trip, and you only average 40 km/h for the first 40 km, what velocity must you average the rest of the way?

Question 712312: If you must average 60 km/h for a 90-km trip, and you only average 40 km/h for the first 40 km, what velocity must you average the rest of the way?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
If you must average 60 km/h for a 90-km trip, and you only average 40 km/h for the first 40 km, what velocity must you average the rest of the way?
:
Find the time required for the trip:
= 1.5 hrs
:
Let s = velocity required for the last 50 km
:
40 km time + 50 km time = 1.5 hrs
+ = 1.5
1 + = 1.5
subtract 1 from both sides
= .5
.5s = 50
s = 100 km/hr required for the last 50 km
RELATED QUESTIONS
On a shopping trip, Marge drove 3 km at 60 km/h, 5 km at 120 km/h and 3 km at 40 km/h/... (answered by MathLover1)

A woman wantes to drive 82 km in 2 h. If she average 38 km/h for the first 1.47 h, what... (answered by josmiceli)

What is your average velocity if you drive a distance of 364 km at a speed of 40 km/h,... (answered by Alan3354)

An automobile travels from point A to point B at a speed of 40 km/h. How fast must it... (answered by malaydassharma)

Peggy drives to town at a rate of 40 km/h. How fast must she drive in order to average 80 (answered by ikleyn,Alan3354)

Peggy drives to town at a rate of 40 km/h. How fast must she drive BACK in order to... (answered by Alan3354,ikleyn)

8. You jog at 9.1 km/h for 5.0 km, then you jump into a car and drive an additional 13... (answered by Alan3354,ankor@dixie-net.com)

You drive on Interstate 10 from Lafayette to Houston, half the time at 56 km/h and the... (answered by solver91311)

Because of traffic Maria could average only 40 km/h for the first 20% of her trip, but... (answered by checkley75)