Question

Lena and Ras drive to work. Lena drives 24 miles in 1.5 hours. Ras drives 36 km in 1 hour 15 min. Work out the difference between their average speeds in km/h. 1 mile = 1.6 km

Answer 1

3.2 km/h

Explanation:

Answer 2

Difference = 3.2 km/h

Explanation:

Given that,

Lena drives 24 miles in 1.5 hours. Ras drives 36 km in 1 hour 15 min.

For average speed of Lena,

d = 24 miles = 38.4 km

t = 1.5 h

`v=(38.4)/(1.5)= 25.6\ km/h`

For average speed of Ras,

d = 36 km

t = 1h 15 min = 1.25 h

`v=(36)/(1.25)=28.8\ km/h`

Difference = 28.8-25.6

= 3.2 km/h

So, the difference between their average speed is 3.2 km/hr.