Question

Out of 555 km, Vishal travelled certain distance by bus and the remaining distance by car. Bus travels with an average speed of `60 (km)/h` and the average speed of car is `75 (km)/h` . He takes total 8 hours to complete the journey . Find the distance the Vishal travelled by bus.

Answer 1

Correct Answer - Vishal travelled 180 km by bus.
Let Vishal travelled x km by bus and y km by car.
Time `= ("distance")/("speed")`
Time taken by Vishal while travelling by bus `= ( x )/( 6) h`.
Time travelling by Vishal while travelling by car `= ( y )/( 75) h ` .
From the given conditions
`x+ y = 555` ....(1)
and `( x)/( 60) + ( y )/( 75) = 8` ...(2)
Multiplying equation (2) by 300,
`5x+ 4y = 2400` ...(3)
We want to find the distance travelled by bus.
So cancel y. Hence multiply equation (1) by ( 4) .
`4x+ 4y = 2220` ...(4)
Subtracting equation (4) from equation (3)
` 5x + 4y = 24000` ...(3)
`underset( -)(" ")4xunderset(-)(+) = underset(-)(" ")2220` ...(4)
`bar( x = 180)`