A mother has 3 kids. Kid A is half the mothers current age. Kid B is 4 years younger than Kid A. In 3 years, kid C will be 1/5 his mothers age (not current age). The sum of all their current ages is the mothers current age. How old is the mothers currently? How old is each of her kids?

A=kid A's age

B=kid B's age

C=kid C's age

m=mother's age

A=m/2

B=A-4

C+3 = (1/5) (m+3)

A+B+C=m

neato

so

we need to use subsitution

C+3=1/5 (m+3)

C = (1/5) (m+3) - 3

interesting

we need to write everything in terms of m

A+B+C=m

(m/2) + A-4 + (1/5) (m+3) - 3=m

(m/2) + (m/2) - 4 + (1/5) (m+3) - 3=m

m-7 + (1/5) (m+3) = m

(1/5) (m+3) = 7

m+3=35

m=32

yay

A=m/2

A=32/2

A=16

B=A-4

B=16-4

B=12

C = (1/5) (m+3) - 3

C = (1/5) (32+3) - 3

C = (1/5) (35) - 3

C=7-3

C=4

mother is 32

Kid A is 16

Kid B is 12

Kid C is 4