Question

Maggie's brother is 5 years younger than three times her age. The sum of their ages is 31. How old is Maggie?

Answer 1

If 5 were added to the sum, it would be 4 times Maggies age.

Maggie is (31+5)/4 = 9 years old.

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Let m represent Maggie's age. Then her brother's age is 3m-5, and the sum of their ages is ...

31 = m + (3m -5)

36 = 4m . . . . . . . simplify and add 5

9 = m . . . . . . . . . divide by 4