Question

Abdul while moving from A to B his speed is 30km/h and on returning from B to A

his speed becomes 20km/h . Find average speed of Abdul for entire trip​

Answer 1

Given :

Method I:

Let the distance traveled by Abdul from home to school = s km

time taken to reach the school=t1 sec

For Return journey , Abdul cover distance =s km

time=t2 sec

∴ Average speed for forward journey[home - school ] = Total distance/ Total time.

20 km/h =s/t1

∴t1=s/20 h ------eq(1)

Average speed for backward journey[school -home] = Total distance/ Total time.

30 km/h =s/t2

t2=s/30h -----eq(2)

Average distance for entire journey = Total distance/ Total time

=(s+s)/[s/20 +s/30]

=2s/s[1/20+1/30]

=2x20x30/50

=24 km/hr

Shortcut method : If equal distance are covered with speeds v1 and v2 then average distance=2v1v2/v1+v2

= 2x20x30/50

=24km/hr

∴ The average speed for Abdul's trip is 24km/h

Answer 2

Answer:

60 is a correct answer mate

Please thanks me 10

Explanation: