Question

A car travels the first 19 km of its journey at

an average speed of 57 km/h and the remaining
55 km at an average speed of 110 km/h. Find the
average speed of the car for its entire journey.

Answer 1

88.8km/h

Explanation:

Since 19 is a third of 57 we divide 60 minutes by 3 which is 20 to find how long it took to drive 19 km.

since 55 is half of 110 I divide 60 minute by 2 to find how long it took drive 55 km.

I add the total time i took to drive which is 50 min but i need to convert it to hours so i do 50/60 then i get the total distance driven (19+55)74km. After i get those i divide 74 by .833333333 which is:

74km/.8333333h=88.8