Question

A tourist first walked 17km with a speed of v km/h. Then he hiked 12 km uphill with the speed that was 2 km/hour less than his original speed. The whole trip took him t hours. What is a formula for t in terms of v?

Answer 1

Answer:
`t=(17)/(v)+(12)/(v-2)`

Explanation:

Given: A tourist first walked 17km with a speed of v km/h.

Since
`Speed=(distance)/(time)`

therefore,
`Time=(distance)/(speed)`

Let
`t_1` be the time he walked with speed v.

then
`t_1=(17)/(v)`

Also he hiked 12 km uphill with the speed that was 2 km/hour less than his original speed.

Let
`t_2` be the time he hiked 12 km,

Then
`t_2=(12)/(v-2)`

The total time for the whole trip is given by:-

`t=t_1+t_2=`

Substitute the values of
`t_1` and
`t_2` in the equation, we get

`t=(17)/(v)+(12)/(v-2)`