a boy travels from A to B With a constant speed 10 kmph and then from B to A with a speed of 20 kmph. Find the average of the boy for the trip
Answers
QUESTION:-
A boy travels from A to B With a constant speed 10 kmph and then from B to A with a speed of 20 kmph. Find the average of the boy for the trip
GIVEN:-
A boy travels A to B with a constant speed 10 km\h and then from B to A with a speed of 20 km\h.
TO FIND:-
the average seed of the boy for the trip
FORMULA USED:-
Distance = Speed × Time
SOLUTION:-
10 km/hr ->
A_B
<--20 km/hr
Let the distance from A to B be X km
The speed of the boy travels A to B = 10 km/hr
We know that
Distance = Speed × Time
= Time = Distance / Speed
= Time taken for traveling from A to B
= X/10 hr.
And
The speed of the boy travels B to A = 20 km/hr
Time taken for traveling from B to A
= X/20 hr
Total distance travelled by the boy
= Distance from A to B + Distance from B to A
= X+X = 2X km
Total time taken for travelling = (X/10)+(X/20)
LCM of 10 and 20 = 20
= (2X+X)/20
= 3X/20 hr
Now , The average speed of the boy
= Total distance / Total time
= 2X/(3X/20)
= 2X×(20/3X)
= (2X×20)/(3X)
= 40X/3X
= 40/3 km /hr
= 13 1/3 km/hr
Hence, The average speed of the boy in the trip is 40/3 km/hr or 13 1/3 km/hour
Hope it helps :D