Question

a person goes to his office by scooter at the speed of 50 km/hr and reaches 10 minutes earlier. if he goes at the speed 40 km/hr, then the reaches 20 minutes late. what will be the speed (in km/hr) of the scooter to reach on time? speed​

Answer 1

Answer:

So required speed = 46.1538461538 km/ hr

Step-by-step explanation:

let the distance between the office and house be X

time taken at speed 50km/hr = X/50

time taken at speed 40km/hr = X/40

difference between the times = X/40 - X/50

which is provided as 20+10 =30 minutes = 1/2 hours

Therefore

X/40 - X/50 = 1/2

multiplying by 10 we get

5X - 40X = 100

X = 100 km

time taken at speed 40km/hr = X/40 = 100 / 40 = 5/2 hours

= 150 minutes

He reaches 20 minutes late.

so to get on time he should cover the same distance in

130 minutes

So required speed = 100 /(130/60)

100 ×60

= ------------

130

= 600÷13

= 46.1538461538 km/ hr