While going to office, Salman travels at a speed of 30 kmph and on his way back, he travels at a speed of 45 kmph. What is his average speed of the whole journey?

Question: While going to office, Salman travels at a speed of 30 kmph and on his way back, he travels at a speed of 45 kmph. What is his average speed of the whole journey?

Solution:
When distance travelled is same, then average speed = (2ab)/(a + b); (where a and b are two different speeds)

∴ The Average Speed = (2 × 45 × 30)/(45 + 30)
= 2700/75 kmph
= 36 kmph