A Hen and a Half

Date: 09/23/98 at 17:49:09
From: Chase
Subject: Math-Problem Solving

Dr. Math,

I am having a hard time trying to find the answer to this problem.  
Will you please help me?

If a hen and a half lays an egg and a half in a day and a half, how 
many eggs will five hens lay in 6 days?

Date: 09/30/98 at 12:45:36
From: Doctor Peterson
Subject: Re: Math-Problem Solving

Hi, Chase. This is an odd problem designed to confuse you. So let's 
try simplifying the problem, and then use what we learn from the 
simpler problem to solve the original.

Suppose two hens lay four eggs in three days. That means that each hen 
laid two eggs during those three days, so each hen lays 2/3 of an egg 
per day. Now if you had five hens and six days, they would lay five 
times as many eggs per day, totalling 10/3 per day; multiply that by 6 
days, and there would be 20 eggs.

Now try doing the same thing with the original numbers. If that still 
confuses you, maybe you can make a general formula if A hens lay B 
eggs in C days, and then just plug in the numbers. When you find the 
answer, it will look simple and surprisingly familiar.

- Doctor Peterson, The Math Forum
  http://mathforum.org/dr.math/