Shaun is 68 miles away from Keegan. They are traveling towards each other. If Keegan travels 7 mph faster than Shaun and they meet after 4 hours, how fast was each traveling?

Answer:vs=5mph, vk=7+vs=12mph

Explanation: kinematics with constant speed

(shaun) xs = 0 + vs*t

(keegan) xk = 68 - vk*t

they meet after t = 4hours (xs=xk):

vs*t = 68-vk*t

but we know that vk=7+vs (keegan faster) replacing:

vs*4 = 68 - (7+vs) * 4

solving vs=5mph, vk=7+vs=12mph