SOLUTION: A bus trip of 90 miles would have taken an hour less if the average speed had been increased by 3 miles per hour. Find the usual average speed of the bus.

Question 1010050: A bus trip of 90 miles would have taken an hour less if the average speed had been increased by 3 miles per hour. Find the usual average speed of the bus.
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = the average speed of the bus
(1)
(2)
-------------------------
(2)
and
(1)
Substitute (1) into (2)
(2)
(2)
(2)
(2)
(2)
(2)
Use quadratic formula

The usual speed is 15 mi/hr
------------------------
check:
(1)
(1)
(1) hrs
and
(2)
(2)
(2)
(2)
(2)
OK
RELATED QUESTIONS
A bicycle trip of 90 miles would have taken an hour less if the average speed had been... (answered by mananth)

A bicycle trip of 90 miles would have taken an hour less if the average speed had been... (answered by mananth)

A bicycle trip of 120 miles would have taken 3 hours less if the average speed had been... (answered by checkley77,themathprof)

Consuela biked 20 miles. If she had increased her average speed by 4 miles per hour, the... (answered by Boreal)

a man made a trip of 432 miles by car. if the average speed had been 6 miles per hour... (answered by mananth)

A bus trip of 450 km would have taken 1 hour less if the average speed for the trip had... (answered by stanbon)

A boy rides a bike 8 miles. The trip would have taken 20 minutes less if he had ridden 2... (answered by nerdybill,stanbon,mangopeeler07)

A man drove a certain distance at a uniform rate. If his rate had been 3 miles per hour... (answered by josgarithmetic)

a car traveled 252 miles averaging a certain speed if the car would have drove six miles... (answered by ankor@dixie-net.com)