5 points
3. When travelling between two
towns, the time taken varies
inversely with the average speed.
When the average speed is 42km/h,
the journey took 4 hours. Find the
average speed if the journey takes 2
hours 20 mins.
0 36km/h
O
45km/h
O
72km/h
O
80km/h​

Respuesta :

Answer: 72km/hr

Explanation:

First let’s find the distance:

d = 42 x 4 = 168

Use the formula to find the average speed: v = d/t

V = 168/2 1/3hr (1/3hr = 20mins)

V = 168 divide by 7/3 (2 1/3 = 7/3)

V = 168 x 3/7

V = 72