Question

The average speed of in a car is 20 km per hr more than the average speed of any bus if the car takes 4 hours less than the bus to cover a distance of 300 km find the average speed of the car and the bus

Answer 1

300/x - 300/x+20 = 40

solve this equation and find ans

Answer 2

Answer:

The bus goes 30 kmph; the car goes 50 kmph  or x = 30

Step-by-step explanation:

Step-by-step explanation:

Formula: Speed = Distance/ Time, Therefore, Time = Distance / speed

Given that speed of the car is 20km/hr more than the average speed of the bus, Let the speed of the bus be x,  

Therefore speed of the car is x+20.

Average speed of the bus:

300/x - 4=300/x+20

=> 300[x+20-x/x(x+20)]= 4

=> 300(20/ x(x+20)) = 4

=> 300(20/x²+20x) = 4 (upon cross multiplying)

=> 6000= 4x²+80x

4x²+80x-6000=0

4(x²  + 20x -1500) =0

x²+20x-1500=0

Upon factorizing,  

(x+50)(x-30)=0

x=30

The bus goes 30 kmph; the car goes 50 kmph