Two cars travel from city A to city B at a speed of 42 and 60 km/hr respectively. If one car takes 2 hours lesser time than the other car for the journey, then the distance between City A and City B is:

Let the distance between City A and City B = $$d$$ km

Speed of first car = 42 km/hr and speed of second car = 60 km/hr

Let time taken by first car = $$t$$ hrs and time taken by second car = $$(t - 2)$$ hrs

Using, speed = distance/time for first car :

=> $$\frac{d}{t} = 42$$

=> $$d = 42t$$ --------------(i)

For second car, => $$\frac{d}{t - 2} = 60$$

Substituting value of $$d$$ from equation (i), we get :

=> $$42t = 60t - 120$$

=> $$60t - 42t = 18t = 120$$

=> $$t = \frac{120}{18} = \frac{20}{3}$$ hrs

From equation (i), => $$d = 42 \times \frac{20}{3} = 280$$ km

=> Ans - (B)