Question 7.

Let the speed of Car 2 be ‘x’ kmph and the time taken by the two cars to meet be ’t’ hours.

In ’t’ hours, Car 1 travels (60 × t) km while Car 2 travels (x × t) km.

It is given that the time taken by Car 1 to travel (x × t) km is 45 minutes or (3/4) hours.

∴ $\frac{(x × t)}{60} = \frac34$ or $t = \frac{180}{4x}$ ….(i)

Similarly, the time taken by Car 2 to travel (60 × t) km is 20 minutes or (1/3) hours.

∴ $\frac{(60 × t)}{x} = \frac13$ or $t = \frac{x}{180}$ ….(ii)

Equating the values in (i) and (ii), and solving for x:

∴ $\frac{180}{4x} = \frac{x}{180} ⟶ x = 90kmph$