Today I am twice as old as my little brother and five years younger than my sister. In 5 years, my older sister will be twice as old as my little brother. In 7 years, I will be ¾ as old as my sister. How old did Shamique turn on her birthday? How old is her brother? How old is her sister?
Assuming Shamique is asking the question, then, in equation form the information is:
S = 2b (1) where S is Shamique's age, b is her brother's age
S = s - 5 (2) where s is her sister's age
s + 5 = 2(b + 5) However, this is not independent information as it can be derived from equations (1) and (2), so we ignore it!
S + 7 = (3/4)(s + 7) (3)
We can now solve equations (1), (2) and (3) for S, b and s.
Can you take it from here?
(You should get S = 8, b = 4 and s = 13).