a man's covers 3 by 7 of his distance by train at the speed of 50 kilometre per hour next to by 5 of his distance by bus speed of 25 kilometre per hour and depending distance by auto at the speed of 20 kilometre per hour find its average speed of journey
Answers
Answered by
2
31.17 km/hr
Step-by-step explanation:
let total distance= LCM (7,5) = 35 km
d1 = 3/7 * 35 = 15 km ,d2 = 2/5 *35 = 14 km
remaining(d3) = 35 - 15-14 = 6 km
t1 = 15/50 = 3/10 , t2 = 14/25 ,
t3 = 6/20 = 3/10
total time taken = 3/10 + 14/25 + 3/10
= (30+56+30)/100 = 116/100
average speed = total distance/total time taken =35/116/100 = 3500/116
= 30.17 km /hr
Similar questions