Question

A journey of 650km is covered in 12 hours. if three fifths of the journey is covered at a speed of 78 km per hour, at what speed is the remaining journey completed ​

Answer 1

Answer:

They have given the total distance and time taken

and 3 journey s speed 78 km/hr

5

There fore

Step-by-step explanation:

First find out the 3/5 distace of the total distance

$\frac{3}{5} \times 650 = 390km$

The 3/5 distance of the total journey

Now we should find the time

By speed formula

$speed = \frac{distance}{time \: taken}$

There fore

$78 = \frac{390}{time} \\ \\ time = \frac{390}{78} \\ \\ = 5hours$

BY Subtracting (Total distance-390=Remaining distance)

(Total time -5hr=remaining time)

The remaining time and distance are

Time--7hr

Distance--260km

By again using speed formula

$speed = \frac{distance}{time \: taken}$

$speed = \frac{260}{7 } \\ speed = 34.14km |hr$

The remaining speed is

34.14km/hr