Question

For the first 30 km, the bicyclist rode with a speed of v km/hour. For the remaining 17 km he rode with a speed which was 2 km/hour greater than his original speed. How much time did the bicyclist spend on the entire trip? Let t be the time (in hours), and find t if:v=15 t in terms of v is

Answer 1

30/v+17/v+2

3hour

Explanation:

....

Answer 2

t in terms of v is
`t=(30)/(v)+(17)/(v+2)`

when v=15, t will be 3

Explanation:

We know that,

`\text{Speed}=\frac{\text{Distance}}{\text{Time}}`

`\Rightarrow \text{Time}=\frac{\text{Distance}}{\text{Speed}}`

For the first 30 km, the bicyclist rode with a speed of v km/hr. So the time taken by the cyclist to cover up 30 km is,

`t_1=(30)/(v)` hr

For the remaining 17 km he rode with a speed which was 2 km/hr greater than his original speed i.e (v+2) km/hr

`t_2=(17)/(v+2)` hr

So the total time is the sum of these individual times. So,

`t=t_1+t_2=(30)/(v)+(17)/(v+2)`

When v=15, t is

`t=(30)/(15)+(17)/(15+2)=(30)/(15)+(17)/(17)=2+1=3`