Question 646234
2 mice eat 2 meals in 2 days, how many mice can eat 18 meals in 6 days?
<pre>
Since 2 mice eat 2 meals in 2 days, those same 2 mice can eat 6 meals in
6 days.  So to get 18 meals eaten in those same 6 days, it will take 3
times as many mice as those 2, or 6 mice.

You can also use the job-worker-time formula, which is:

{{{(W[1]T[1])/J[1]}}}{{{""=""}}}{{{(W[2]T[2])/J[2]}}}

where

W<sub>1</sub> = the number of workers in the first situation.
T<sub>1</sub> = the number of time units (days in this case) in the first situation.
J<sub>1</sub> = the number of jobs in the first situation.

W<sub>2</sub> = the number of workers in the second situation.
T<sub>2</sub> = the number of time units (days in this case) in the second situation.
J<sub>2</sub> = the number of jobs in the second situation.

The workers here are mice.  The jobs are meals eaten.

W<sub>1</sub> = 2            W<sub>2</sub> = the unknown quantity     
T<sub>1</sub> = 2            T<sub>2</sub> = 6 
J<sub>1</sub> = 2            J<sub>2</sub> = 18

{{{(W[1]T[1])/J[1]}}}{{{""=""}}}{{{(W[2]T[2])/J[2]}}}

{{{(2*2)/2}}}{{{""=""}}}{{{(W[2]*6)/18}}}

      2 = {{{(W[2]*6)/18}}}

      2 = {{{(W[2])/3}}}
      
Multiply both sides by 6

      6 = W<sub>2</sub>

Answer: 6 mice.

Edwin</pre>