Question

The distance between two milestones is 230 km and two cars start simultaneously from the milestones in opposite directions. The distance between them after three hours is 20 km. If the speed of one car is less than that of other by 10 km/hr, find the speed of each car.

• A. 25 km/hr, 40 km/hr
• B. 40 km/hr, 50 km/hr
• C. 20 km/hr, 40 km/hr
• D. 30 km/hr, 40 km/hr

Answer 1

The correct option is D

30 km/hr, 40 km/hr

Let speed of one car be x km/hr
$\therefore$ Speed of second car = (x - 10) km/hr

Distance travelled by first car in 3 hours = 3x km
Distance travelled by second car in 3 hours = 3(x-10) km
$\therefore$ 3x + 3(x-10) + 20 = 230
3x + 3x – 30 + 20 = 230
3x + 3x – 10 = 230
6x = 240
x = 40.
$\therefore$ Speed of first car = 40 km/hr
And speed of second car = 40 - 10 = 30 km/hr