SOLUTION: A car travels a distance of 9000 KM with a certain average speed. If after travelling half the distance the average speed of the car be increased by 15 Km/Hrs., the time required t
Algebra.Com
Question 720636: A car travels a distance of 9000 KM with a certain average speed. If after travelling half the distance the average speed of the car be increased by 15 Km/Hrs., the time required to travel 900 Km, is reduces by 11/2 hour, find the original average speed of the car.
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
Time = distance /speed
original speed = x
450x-450(x+15) = (-3/2) ( x*(x+15)
-6750=(-3/2)(x^2+15x)
-13000=-3x^2-45x
3x^2+45x-13500=0
/3
x^2+15x-4500=0
x^2+75x-60-4500-0
(x+75)(x-60)=0
x= 60 km/h the original speed
RELATED QUESTIONS
A car travels a distance of900 km with a certain average speed. After travelling half the (answered by Alan3354)
a car travels certain distance at a speed of 30 km/h and returns with a speed of 10 m/s... (answered by Fombitz)
A CAR TRAVELLING AT AN AVERAGE SPEED OF 100 KM/H COVERS A CERTAIN DISTANCE IN 3 HOURS 36... (answered by solver91311)
If a car travels a distance of 50 km in 30 minutes what is the average... (answered by ewatrrr)
a car travels a certain distance with a speed of 50km/h and return with a speed of 40... (answered by Alan3354)
93. A car travels the first one-third of a certain dis-.tance with a speed of 10 km/hr,... (answered by ankor@dixie-net.com)
A car travels a total distance of 180 km. After traveling a certain distance, the car... (answered by ankor@dixie-net.com)
a car travels at 60 km per hour over a certain distance , and then returns over the same... (answered by mananth)
A train travels at a certain average speed for a distance of 63 km. Thereafter it travels (answered by josgarithmetic)