Question

Two cars are traveling down the highway with the same speed. If the first car increases its speed by 1km/hr, and the other car decreases its speed by 10km/hr, then the first car will cover the same distance in 2hrs as the second car in 3hrs. What is the speed of the cars?

Answer 1

The speed of the cars is
`32 (km)/(h)`

Explanation:

First we must first have the clear concept that
`speed=(distance)/(time)` or
`s=(d)/(t)`

Our question is the speed of the cars then the variable to clear will be s.

Let's raise the equation for each car taking into account that we have the following data:

Car 1:
`s_(1)=s+1` ,
`t_(1)=2` and
`d_(1)= d_(2)`

Car 1:
`s_(2)=s-10` ,
`t_(2)=3` and
`d_(1)= d_(2)`

The two cars travel the same distance so we will raise the distance formula for each car and then match them.

Car 1

`d_(1)=s_(1)*t_(1)`

`d_(1)=(s+1)*2`

`d_(1)=2s+2`

Car 2

`d_(2)=s_(2)*t_(2)`

`d_(2)=(s-10)*3`

`d_(2)=3s.30`

`d_(1)=d_(2)`

`2s+2=3s-30`

`2+30=3s-2s`

`32=s`

The speed of the cars is 32 km/hr