SOLUTION: A train normally travels 60 miles at a certain speed. one day,due to bad weather, the train's speed is reduced by 10mph so that the journey takes 3 hours longer. find the normal sp

Question 165692: A train normally travels 60 miles at a certain speed. one day,due to bad weather, the train's speed is reduced by 10mph so that the journey takes 3 hours longer. find the normal speed?
Answer by checkley77(12844) (Show Source): You can put this solution on YOUR website!
D=RT
60=RT
R=60/T
60=(R-10)(T+3)
60=(60/T-10)(T+3)
60=60T/T+180/T-10T-30
60=60+180/T-10T-30
60-60+30=180/T-10T
30=(180-10T^2)/T
30T=180-10T^2
10T^2+30T-180=0
10(T^2+3T-18)=0
10(T+6)(T-3)
T-3=0
T=3
R=60/3
R=20 MPH
PROOF:
60=(20-10)(3+3)
60=10*6
60=60

RELATED QUESTIONS
A train normally travels 60 miles at a certain speed. One day, due to bad weather, the... (answered by ankor@dixie-net.com)

a train normally travels 240km at a certain speed. one day, due to bad weather, the... (answered by Alan3354,stanbon)

Q4. A train runs miles at a speed of 30mph, another 50 miles at a speed of 40mph, then... (answered by richwmiller)

Hello The speed of train A is 10mph slower than train B. Train A travels 230 miles in (answered by checkley77)

A freight train leaves a station and travels due east at a speed of 60 mph. One hour... (answered by Alan3354)

A train goes a distance of 120 miles at a certain speed. If the train had gone 10mph... (answered by ankor@dixie-net.com)

The speed of a passenger train is 10mph faster than the speed of a freight train. The... (answered by checkley77,J.A.Romero)

The speed of a passenger train is 10mph faster than the speed of a freight train. The... (answered by stanbon)

Train a is 10mph slower than train b. Train a travels 210 miles in the same time that... (answered by ewatrrr,solver91311)