Question

a boy cycles 42 km in 2 hours 20 minutes his speed in km/h is?​

Answer 1

Answer:

Let the distance between the school and the house is x km

Speed of the boy from house to school =42 km/hr.

Using formula, Time taken =

speed

distance

.

So, time taken =

20

x

hours.

Also,Speed of the boy from school to the house =30 km/hr

So, time taken =

30

x

hours.

Total time taken =

20

x

+

30

x

=

12

x

hours

Also total distance covered by boy =x+x=2x km.

Using formula,

Average speed =

Totaltime

Totaldistance

=

12

x

2x

=20 km/hr.

Thus, average speed of the boy's journey is 20 km/hr.

Answer 2

Step-by-step explanation:

d=42km

t=2 hr 20 min.=7/3hr

s=?

S=d/t

S*(18/5)=42/(7/3)

S*(18/5)=126/7

S=(126/7)*(5/18)

s=35/7

S=5 km/hr