Question

Two cars leave town at the same time and travel in opposite directions. Speed of car A is 12 km/h more than car B. They are 312km apart after 4 hours. Find the speed of each car.​

Answer 1

Speed of car B is 33 km/h and speed of car A is
`45\,\,km/h`

Explanation:

Let speed of car B be
`x` km/h

Speed of car A is 12 km/h more than car B.

Therefore,

Speed of car A =
`(12+x)` km/h

Distance = Speed × Time

Distance travelled by car A in 4 hours =
`4(12+x)` km =
`(48+4x)` km

Distance travelled by car B in 4 hours =
`4x` km

Also, cars A and B are 312km apart after 4 hours.

`48+4x+4x=312\\48+8x=312\\8x=264\\\\x=(264)/(8)\\\\x=33\,\,km/h`

Speed of car B is 33 km/h and speed of car A is
`12+x=12+33=45\,\,km/h`