Question

A girl is cycling and she covers $0.5km$ in $2$ minutes, next $0.75km$ in $3$ minutes and last $1$ km in $4$ minutes. Find the average speed.

• A. 4.16m/s
• B. 8.24m/s
• C. 9m/s
• D. 6.32m/s

Answer 1

The correct option is A

4.16m/s

In the first part of the journey, the distance covered = $0.5km$ and time = $2$ minutes

In the second part of the journey, the distance covered = $0.75km$ and time = $3$ minutes

And, In the third part of the journey, the distance covered = $1km$ and time = $4$ minutes

So total distance covered = $2.25km$ and total time = $9$ minutes

So,average speed = $\frac{\text{total distance}}{\text{total time}}$

= $\frac{2.25}{9}=0.25km/min$

And,$1km=1000m$ and $1min=60s$

So average speed in $m/s$ = $\frac{0.25\times 1000}{60}=4.16m/s$