Question

a jay while driving to school computes the average speed of this trip to be 20 km/h on his return trip aong the same root ,there is less traffic and the average sped is 30 km/h what is the average speed for ajay 's trip

Answer 1

Answer:

Average speed=Total distance/Total time

S1=20 Km/h,S2=30 Km/h so now let us assume that the distance between a and b will be 60 km (LMC of 20 and 30) D1=60,D2=60 Total distance= D1+D2=60+60=120 KM now T1=D1/S1). T1=120/20=6Hr. T2=D2/S2. T2=120/30=4Hr. Total time=T1+T2=6+4=10Hr. now Average speed= Total distance +Total time =120/10. AVERAGE SPEED=12