Question

A man travelled a distance of 80kms in7hrs partly on foot at the rate of 8kmph and partly on bicycle at 16kmph what is the distance travelled by foot?

Answer 1

32km on foot

let x be foot hours and y be bike hours

8x + 16y = 80

x + y = 7

y = 7 - x

substitute equation 3 in equation 1 you get

8x + 16(7-x) = 80

8x + 112 - 16x = 80

bring variables to 1 side and numbers to another

16x - 8x = 112 - 80

8x = 32

x = 4

Therefore, the man travelled 4 hours at the speed of 8kmph

distance = speed * time

= 8 * 4

= 32km