Question

A girl moves with a speed of 6 km/hr for 2h and with a speed of 4 km/h for the next 3h. Find the average speed of the girl and the total distance moved.

Answer 1

Hope this answer helps you!!!!

Answer 2

The average speed of the girl is 4.8 km/h and the total distance is 24 km.

The girl moves with different velocity in different span of time. The average speed is calculated by knowing total distance covered in total time.

Given:

Speed 1 = 6 km/hr  

Time 1 = 2 hr

Speed 2 = 4 km/hr

Time 2 = 3 hr

As we know that $Distance =\text { speed } \times { time }$

$Distance\ d1 =\text { speed } 1 \times \text { time } 1$

$\begin{array}{l}{d 1=6 \times 2} \\ {d 1=12\ \mathrm{km}}\end{array}$

$\mathrm{d} 2=\text { speed } 2 \times \text { time } 2$

$\begin{array}{l}{\text {distance } d 2=4 \times 3} \\ {d 2=12\ \mathrm{km}}\end{array}$

Total distance covered = d1 + d2

Total distance d = d1 + d2

d = 12 + 12

d = 24 km  

Total time t = time1 + time2

t = 2 + 3

t = 5 hr

Average speed = Total distance / Total time

$\begin{array}{l}{=\frac{d}{t}} \\ \\ {=\frac{24}{5}} \\ \bold{=4.8 \mathrm{km} / \mathrm{hr}}\end{array}$