Five years from now, the sum of the ages of a woman and her daughter will be 40 years. The difference in their present age is 12 years. How old is her daughter now?
M - D = 12,
[M + 5] + [D + 5] = 40, solve for M, D
M = 21 - Mother's age now
D = 9 - Daughter's age now
Note: You mean the Mother gave birth to her daughter when she was 12 years old??! Did you make this question up?