Problema Solution

mark is going for a bike ride and he is trying to catch up to his friend who is 20 miles ahead if him. his friend is biking at a rate of 12 miles per hour. mark rides at a speed of 16 miles per hour. how long before mark catches up to his friend

Answer provided by our tutors

let 'x' represent the distant his friend rides, then 'x+20' represents the distant Mark rides, so the friends will ride together after:

(x+20)12=16x

click here to solve for the distance

x=60

Mark has been riding at 16 mph for 60 miles, so we divide miles by 'miles per hour' in order to cancel 'miles' is and solve for 'hours', the time it took for the friends to catch up:
60/16

slick here to simplify

3.75

It took 3.75 hours for Mark to catch up to his friend.