Question

A man walks at the speed of 5 km/h and runs at the speed of 10 km/h. How much time will be man require to cover the distance of 28 km, if he covers half (first 14 km) his journey walking and half his journey running? 8.4h 6h 5h 4.2 h 5.5 h

Answer 1

the answer is 4.2h.....and this is perfect answer
....hint..use TIME=DIST/SPEED+DIST2/SPEED2..T= 14/5+14/10=4.2H

Answer 2

Answer:  4.2 h.

Step-by-step explanation:

Since,

$\text{Time}=\frac{\text{Distance}}{\text{Speed}}$

When he walked,

The speed = 5 km/h

Distance = 14 km ( Half of 28 km)

⇒ The time taken by him in walking = 14/5 = 2.8 hours

When he ran,

The speed = 10 km/h

Distance = 14 km ( Half of 28 km)

⇒ The time taken by him in running = 14/10 = 1.4 hours

Hence, the total time taken by him in the journey = 2.8 hours + 1.4 hours

= 4.2 hours.