word problem of linear equations

Question

the ages of two friends A & B differ by three years. A's father D is twice old as A and B is twice as old as sister C. the ages of C and D differ by 30 yrs. find the ages of A and B?

Answer 1

A is 21 years old while B is 24 years old =)

Answer 2

Philomena is asking people for money for a trust fund; she tells the first person; give me as much money as I have in my pocket and I'll put the money in the trust fund; she tells the same thing to the second and third person; and then she is left with no money of her own, but she has thirty dollars accumulated for the trust; how much money did she had to begin with?