Question

A cyclist pedals from house to college at speed of 10 km/hr and return at a speed of 15 km/hr. the average speed in km/hr is:

Answer 1

Answer:

here your answer is...

Step-by-step explanation:

average speed = sum of all speeds/no.of speeds

= 10+15/2

=25/2

=12.5 km/hr

hence average speed is 12.5 kmph.

HOPE IT HELPS YOU...

Answer 2

Given :

Speed while going from house to college = 10 km/hr

Speed while returning = 15 km/hr

To Find :

The average speed in km/hr

Solution :

Let the distance between house and college be 'x'

Total distance covered = (x + x) = 2x

[As the cyclist goes college from his house and returns to the house]

Time taken by the cyclist to go college (T$_{1}$) = $\frac{Distance}{Speed}$ = $\frac{x}{10}$ hr

Time taken by the cyclist to return to house from college (T$_{2}$) = $\frac{x}{15}$

Total Time taken by the cyclist = T$_{1}$ + T$_{2}$

                                                   = $\frac{x}{10} + \frac{x}{15}$

                                                   = $\frac{15x + 10x}{150}$

                                                   = $\frac{25x}{150}$

                                                  = $\frac{5x}{30}$ hrs

Average Speed = $\frac{Total Distance Covered}{Total Time Taken}$

                          = $\frac{2x * 30}{5x}$

                          = 12 Km/hr.

∴ The average Speed of the cyclist is 12 Km/hr.