Question

a boy travels with a speed of 30 kilometres per hour for first one by three journey time during the remaining journey time he travel speed 60 kilometres find the average speed of the boy​

Answer 1

ans. 45 km/h

let us consider that distance travelled by boy is 90 km

first 30 km by 30km/h = 1 hour

after that 60 km in 1 hour

avg. velocity =

distance travelled/time taken

=30+60/1+1

45km/h