I go to my school which is 5 km away from my home at a speed of 10 km/h and return home at the speed of 15 km/h. What is my average speed?

Correct option is A

Given:

Distance from home to school = 5 km

Speed while going = 10 km/h

Speed while returning = 15 km/h

Formula Used:

For equal distances,

Average speed = $$\frac{2ab}{a+b}$$​​

where (a) and (b) are the two speeds.

Solution:

Let

a = 10 km/h, b = 15 km/h

Average speed = $$\frac{2 \times 10 \times 15}{10 + 15}$$​​

= $$\frac{300}{25}$$​​

= 12 km/h