Question

a student while going in a school bus observes the average speed to be 20km/h. on his way trip along the same way the average speed is 30km/h . what is the average speed of the bus in the entire journey?
PLEASE ANSWER I WILL MARK AS BRAINLIEST!!!!!​

Answer 1

$\sf{Let\: us \:assume \:that\: the\: student\: is\: travelling}$$\sf{ x\: kilometer\: distance \:while\: going\: to\: school.}$

$\sf\large{\underline{\underline{We\:know\:that:}}}$

$\sf\red{\implies Distance = Speed \times Time }$

1️⃣.$\sf{ It's\: average\: speed \:is \:20\: km\:{h}^{-1}}$

$\sf{\implies x = v1 \times t1 = 20 \times t1}$

2️⃣. $\sf{when\: it's \:Average \:speed\: is \:30 \:km\:{h}^{-1}}$

$\sf{\implies x = v2 \times t2 = 30 \times t2 }$

$\sf\large{\underline{\underline{Therefore:}}}$

$\sf{\implies Average\: Velocity = \dfrac{total\:distance\:travelled}{total\:time\:taken}}$

$\sf{\implies Average \:Velocity = \dfrac{x + x}{\dfrac{x}{v1} + \dfrac{x}{v2}} = \dfrac{2x}{\dfrac{x}{20} + \dfrac{x}{30}} = 24 \:km\:{h}^{-1}}$