Problema Solution
6. Mary is 24 years old. She is twice as old as Ana was when Mary was as old as Ana is now. How old is Ana?
Answer provided by our tutors
Let a = Ana's age now.The difference between their ages NOW is 24-a.
24 - a years ago, Mary was a years old, while Ana was a-(24-a) = 2a - 24.
During that time, a = 2(2a-24), or a = 4a - 48, or 3a = 48, or a = 16.
Thus Ana is 16 years old now.