Question

a car travels from a to b at the rate of 10 km/our but it's comes back at the rate of 20 km/hr find the average speed of the car​

Answer 1

Given:

a car travels from a to b at the rate of 10 km/hr

it's comes back at the rate of 20 km/hr

find the average speed of the car​

Let distance from A to B be x

Time for travel from A to B=x/10

Time for travel from B to A=x/20

For total distance 2x is

$2x=\frac{2x}{\frac{x}{10}+ \frac{x}{20} }$

$=\frac{2x}{\frac{20x+10x}{20\times10} }$

$=\frac{2x}{\frac{30x}{200} }$

$=\frac{2x\times200}{30x}$

$=\frac{2\times20}{3}$

$=\frac{40}{3}$

=13.33km/hr

Hence the average speed of the car is 13.33km/hr

Answer 2

From the given question the correct answer is:

the average speed of the car​ is 13.33.

Given:

a car travels from a to b at the rate of 10 km/hour but it's coming back at the rate of 20 km/hr

To find:

the average speed of the car​

Solution:

Let the distance from A to B be x

Time for travel from A to B=x/10

Time for travel from B to A=x/20

For total distance 2x is

$2x=\frac{2x}{\frac{x}{10}+\frac{x}{20} }$

$=\frac{2x}{\frac{20x+10x}{20\times10} }$

$=\frac{2x}{\frac{30x}{200} }$

=$\frac{2x\times200}{30x}$

=$\frac{2\times20}{3}$

=40/3

=13.33

Hence, the average speed of the car​ is 13.33.