Question

A car travels the first half of a distance with the speed of 40 kilometre per hour the next the next half with a speed of 90 kilometre per hour. Find the average speed of the car for the total journey. *

Answer 1

Answer:

The answer is 60km/hr

Explanation:

Let x=total distance covered by the car ,

Time taken to complete first half distance with speed V1=40km/hr

t1=x/2×40 = x/80 hr ......(1)

Time taken to complete next half distance with speed V2=90km/hr

t2=x/2×90 =x/180 hr ......(2)

• The total time t =t1+t2

t=x/80+x/180

Vavg =x/x(1/80+1/180)=1/80+1/180

Vavg =720/13=55.9

Vavg=60km/hr

HOPE IT HELPS YOU

Answer 2

Let the total distance covered in the

journey be x

$\implies$ Time taken to complete half distance with speed V1 ( V1 = 40 kmph)

$\: = \: T1 \: =$$\frac{x}{2} \times \frac{1}{40}$

$\: = \: T1 \: = \: \frac{x}{80}$