Question

A train travels 120km in 2hours 30minutes. Calculate it's average speed

Answer 1

$\Large {\underline { \sf {Answer :}}}$

48 km/h

$\Large {\underline { \sf {Explication \; of \; steps :}}}$

As per the provided information in the given question, we have :

• Total distance travelled = 120 km
• Total time taken = 2 hours 30 minutes

We are asked to calculate its average speed.

Before commencing the steps to calculate average speed, let's convert total time taken fully into hrs.

Here,

➝ Total time = 2 hours 30 minutes

• 30 minutes is considered as half an hour.

➝ Total time = 2 + $\sf \dfrac{1}{2}$ hrs

➝ Total time = $\sf \dfrac{4 +1}{2}$ hrs

➝ Total time = $\sf \dfrac{5}{2}$ hrs

⇒ Total time = $\pmb{\sf {\dfrac{5}{2}}}$ hrs

Now, let's calculate average speed.

★ Calculating average speed :

Average speed refers to total distance divided by total time. That is,

$\boxed{\sf {Speed_{(avg)} = \dfrac{Total \; s }{Total \; t} }}$

• s denotes distance
• t denotes time

Substituting the values we have,

$\longrightarrow \sf { Speed_{(avg)} = \dfrac{120 \; km }{\cfrac{5}{2} \; hrs} }$

$\longrightarrow \sf { Speed_{(avg)} = \cancel{120} \times \dfrac{2}{\cancel{5}} \; km/h}$

$\longrightarrow \sf { Speed_{(avg)} = (24 \times 2 ) \; km/h}$

$\longrightarrow \underline{\boxed{\sf { Speed_{(avg)} =48 \; km/h}}}\; \bigstar$

Therefore, average speed of the train is 48 km/h.