Albert and his good buddy Brad are both mechanics at a shop that does oil changes. They are

in a friendly competition to see who can complete the most oil changes in one day. Albert has

already finished 6 oil changes today, and can complete more at a rate of 1 oil change per

hour. Brad just came on shift, and can finish 3 oil changes every hour. Sometime during the

day, the friends will be tied, with the same number of oil changes completed. How long will

that take?