Question

Arjun drove for 4 hours at a Speed of 80 km per hour and for 4 hours at 100 km per hour. What was his average speed for the whole journey?

Answer 1

✰ Answer:-

Given:-

• Arjun drove 4 hours at a speed of 80 km per hour and 4 hours at a speed of 100 km per hour.

To Find:-

• The average speed of Arjun for the whole journey.

Concept:-

• $Average\;Speed=\frac{Total\;Distance}{Total \;Time}$

Solution:-

• Distance = Speed × Time

→ Total distance = 80 × 4 + 100 × 4

= 320 + 400

= 720 km.

→ Total time = 4 + 4

= 8 hrs.

So,

→ Total distance = 720 km  

→ Total time = 8hrs

Hence,

$Average\;Speed=\frac{Total\;Distance}{Total \;Time}$

$= \frac{720}{8}$

= 90 km/h

Therefore,

∴ The average speed of Arjun throughout the journey will be = 90 km/hr.

__________________________