# A car is travelling at a rate of 70 km per hour leaves the house 2 hours after a truck has left and overtakes it in 5 hours. At what rate was the truck travelling?

Jul 23, 2017

The speed of the truck is $= 50 k m {h}^{-} 1$

#### Explanation:

Let the speed of the truck be $= v k m {h}^{-} 1$

The distance travelled by the truck is

$d = v \cdot 7 = 7 v k m$

The distance travelled by the car is

$d = 5 \cdot 70 = 350 k m$

Therefore,

$7 v = 350$

$v = \frac{350}{7} = 50 k m {h}^{-} 1$