Correct Answer - Option 4 : 11 km/hr
Given:
The speed of bike C is one less than the speed of bike B.
The speed of bike B is one less than the bike A.
Amit travelled 330 km with bike A.
He travelled a distance which is 120 km less than the previous distance on bike B and the distance he travelled on bike C was 60 km more than the distance he travelled at bike B.
He took a total time of 81 hours to travel the entire distance on 3 bikes.
Formula Used:
Distance = time x speed
Calculation:
Let the speed of bike A be x km/hr, then speed of bike B will be (x – 1) km/hr, and speed of bike C be (x – 2) km/hr.
ATQ,
330/x + 210/(x – 1) + 270/(x – 2) = 81
Checking and putting the options in the above equation, it can be shown that x = 11 satisfies the equation.
∴ Speed of the bike A is 11 km/hr.
