First we have to convert the first number into a fraction.
1 1/2 = 3/2
Then we multiply 3/2 by 12 . Applying the rules of fractions would be 3*12/2 =18.
18 is the number of people
Then we change 4 1/2 into a fraction. So it is equivalent to (4*2+1)/ 2 = 9/2
Finally We divide the pounds 9/2 on the number of people 18.
(9/2) /18 =9/36
simplifying we obtaing 1/4
We obtain 1/4 pound for each person