Roger can run one mile in 18 minutes. jeff can run one mile in 15 minutes. if jeff gives roger a 1 minute head start, how long will it take before jeff catches up to roger?

Respuesta :

Alright, lets get started.

Roger can run one mile in 18 minutes.

Jeff can run one mile in 15 minutes.

Suppose in x minutes, they both will catch up.

Roger runs in 18 minutes = 1 mile

So, Roger will run in 1 minute = [tex]\frac{1}{18}[/tex] miles

So, Roger will run in x minutes = [tex]\frac{x}{18}[/tex] miles

Jeff runs in 15 minues = 1 mile

So, Jeff will run in 1 minute = [tex]\frac{1}{15}[/tex] mile

As Jeff gives roger a 1 minute head start, means Jeff will have x-1 minute time to run

So, Jeff will run in (x-1) minute = [tex]\frac{x-1}{15}[/tex]

As both are cathing up means they both runs same distance, means

[tex]\frac{x}{18} =\frac{x-1}{15}[/tex]

Cross Multiplying

[tex]15 x = 18x - 18[/tex]

[tex]3 x = 18[/tex]

x = 6 minutes

So for calculating distance = [tex]speed * time[/tex]

Distance = [tex]\frac{1}{18} *6 = \frac{1}{3}[/tex] miles

It means it will take 1/3 or 0.33 miles before jeff catches up to roger.   :   Answer

Hope it will help :)