Question

A car travel 100km at a uniform speed of 40km/h and the next 125km at a uniform speed of 50km/h . find average speed of car

Answer 1

☆ hey mate ☆

let

the distance travelled by car at 1st part = d1

=> d1 = 100km

speed of the car at 1st part = s1

=> s1 = 40kmph

time taken for 1st part (T1) = d/s = 100/40 = 2.5hours

now ,

let the distance travelled by the car in next part = d2

=> d2 = 125km

let the speed of the car in next hour = s2

=> s2 = 50kmph

time taken in next hour ( T2 ) = d/s = 125/50 = 2.5 hours



nooowww

average speed = ( d1 + d2 ) / ( T1 + T2)

=> [100 + 125 ] / ( 2.5 + 2.5)

=> 225 / 5

=> 45 kmph

there fore the average speed of the car = 45 kmph