Question

A bus covers a certain distance in 3 hours 20 minutes at an average speed of 45 km/h. How long will it take to cover the same distance at a speed of 36 km/h? ​

Answer 1

GIVEN :–

• A bus covers a certain distance in 3 hours 20 minutes at an average speed of 45 km/h.

TO FIND :–

• How long will it take to cover the same distance at a speed of 36 km/h ?

SOLUTION :–

→ A bus covers a certain distance in 12000 second at an average speed of 12.5 m/sec.

$\\ \implies \large {\boxed{\bf Speed=\dfrac{Distance}{Time}}}$

• Now put the values –

$\\ \implies \bf 12.5 =\dfrac{Distance}{12000}$

$\\ \implies \bf Distance=12.5 \times 12000$

$\\ \implies \bf Distance=150000\:m$

• Now –

$\\ \longrightarrow \bf New\:\:speed = 36 Km/hr = 10 m/s$

$\\ \longrightarrow \bf Distance=150000 \:\:m$

$\\ \implies \bf 10=\dfrac{150000}{Time}$

$\\ \implies \bf Time=\dfrac{150000}{10}$

$\\ \implies \bf Time=15000\:\:second$

$\\ \implies \bf Time= \dfrac{15000}{60} \:\:Minutes$

$\\ \implies \bf Time= 250\:\:Minutes$

$\\ \implies \bf Time=\dfrac{250}{60}\:\:hours$

$\\ \implies \large {\boxed{ \bf Time=4\:hours\:10\:Minutes}}$

✯ Hence , 4 hours 10 minutes will it take to cover the same distance at a speed of 36 km/h .

Answer 2

Given:

⟹A bus covers a certain distance in 3 hours 20 minutes at an average speed of 45 km/h.

To Find:

⟹How long will it take to cover the same distance at a speed of 36 km/h?

SOLUTION:

$\begin{gathered}\bold{For \: speed \: of \: 45 \: kmh : } \\ \implies Distance = Speed \times Time \\ \\ \implies D= \cancel{45} \times \frac{10}{\cancel3} \\ \\ \bold{\implies D = 150 \: km} \\ \\ \bold{For \: speed \: of \: 36 \: kmh : } \\ \implies Time = \frac{Distance}{Speed} \\ \\ \implies t = \frac{150}{36} \\ \\ {\implies T= 4 \frac{1}{6} \: hours} \\ \\ \it \: {\therefore Time \: taken = 4 \: hour \: 10 \: minutes}\end{gathered} \\ </p><p>$