Question

Distance between two places A and B is 210 km. Two cars start simultaneously from A and B in opposite direction and distance between them after 3 hours is 54 km. If speed of one car is less than that of other by 8 km/hr, find the speed of each.

Answer 1

Let the speed of car starts from A be x km/h.

Then, speed of car starts from B = (x + 8) km/h

Given, distance between the cars after 3 h = 54 km

According to the question,

Total distance between A and B – Total distance covered by both cars in 3 h = 54

⇒ 210 – [3x + 3(x + 8)] = 54   ...[∵ Distance = Speed × Time]

⇒ 210 – 3x – 3x – 24 = 54

⇒ – 6x = – 210 + 24 + 54

⇒ – 6x = – 210 + 78

⇒ – 6x = – 132

⇒ x = `- 132 xx ((-1)/6)`

∴ x = 22

Hence, the speed of car starts from A = 22 km/h

And the speed of car starts from B = 22 + 8 = 30 km/h