Maggie's brother is 10 years younger than twice her age. The sum of their ages is 29. How old is Maggie? Maggie is ___years old.

Let M be the age of Maggie and B the age of her younger Brother:

Rewrite the problem from English language to Math's:

B = 2. M - 10 (1)

and M + B = 29 (Given) OR B = 29 - M (2)

Plug 2) into 1):

29 - M = 2. M - 10

29 + 10 = 3 M →→3M = 39 and M = 39/3 = 13

Replace M by 13 and you will find B = 6

Then Maggie = 13 year old and her brother B = 6 year old