Answer:
$21
Explanation:
let the money in her purse be $x
1/3 of the money is 1/3x
Since his father gave him $5 and the total amount became $12
the expression for the total amount would be
12= 1/3x+5
We can now solve for x
12-5= 1/3x
1/3x= 7
cross multiply we have
x= 7*3
x= $21
Therefore the money in joes mother's purse is $21