Question

3.) AI 65 kom hr. Alfred can reach home in 50 minutes. At what speed should he drive his car

so that he can reach home 10 minutes earlier?​

Answer 1

He should drive his car at a speed of 81.25 kilometers per hour.

Explanation:

With a velocity of 65 kilometers per hour, he reaches home in 50 minutes. What speed he needs to reach home 10 minutes earlier, that is, in 50 - 10 = 40 minutes?

To solve this, we use the relation between inverse proportion variables(as the velocity increases, time needed decreases), that is, a rule of three with line multiplication, instead of cross. So

65 kilometers per hour - 50 minutes

x kilometers per hour - 40 minutes

So

`40x = 65*50`

`x = (65*50)/(40)`

`x = 81.25`

He should drive his car at a speed of 81.25 kilometers per hour.