Expert: Lynn Houston - 2/22/2010

Question
Hello:

If one person can eat a pie in 6 days, he has eaten 1/6 of the pie per day (Divide pie and 6 days by 6 to get 1/6 pie and 1 day).

Likewise, if 2 people can eat a pie at the same rate in 6 days, have they both eaten 1/6 of the pie in 6 days or each one has eaten 1/12 of the pie per day 1/12 = 1/2 X 1/6?

I thank you for your reply.

Answer
TOGETHER they have eaten 1/6 of the pie in one day, so each one has only eaten 1/12 of the pie in one day.  Think of it this way... if together they can eat the pie in 6 days (eating at the same rate), then for just one to eat the pie alone, it will take twice as long (ie. 12 days), so each eats 1/12 of the pie per day.