Question

If a bicyclist is traveling at a speed of 10 km/h, he will be late by 1 hour. If he will travel at a speed of 15 km/h, then he will arrive an hour early. How fast should he travel to arrive on time?

Answer 1

Answer:

The speed should he travel to arrive on time is 12 km/h  

Step-by-step explanation:

Given as :

Let the time taken by bicyclist = T h

If bicyclist travel with speed 10 km/h,

Then the time taken by him = ( T + 1 ) hours

Again

If bicyclist travel with speed 15 km/h ,

Then the time taken by him = ( T - 1 ) hours

Now Let The distance cover by bicyclist = D km = Speed × Time

So, As The distance cover is same for both case

∴  10 × (T + 1 ) = 15 × (T - 1)

Or, 2 × (T + 1 ) = 3 × (T - 1)

Or,  2 T + 2 = 3 T - 3

Or,  3 +2 = 3 T - 2 T

∴   T = 5 hour

So, Distance cover by bicyclist = D = 10 × (5 + 1 )

Or,                                                 D = 60 km

So, new speed of bicyclist with time 5 hour and distance cover 60 km

    New Speed = $\frac{Distance}{Time}$

Or,  New Speed = $\frac{60}{5}$

∴     New Speed = 12 km/h

Hence The speed should he travel to arrive on time is 12 km/h   Answer