Question

A motorist does the first part of his journey at an average speed of 54km/hour. he then increases his speed to 60 km/h for the rest of the journey . if he travel 255 km in 4 hours, what is the distance travelled for the first part of the journey​

Answer 1

Answer: 135 km

Step-by-step explanation:

d = 54t

225-d = 60(4-t)

225-d = 240 - 60t

60t -d= 15

60t-54t = 15

t = 15/6 = 2.5 hrs

d=2.5*54 = 135 km