Tom is twice as old as Sally's age when he was the age that Sally is now Tom is now 24 How old is Sally now According to the book the answer is 18 but we think the right answer should be 16?

Book answer: Tom now 24, Sally now 18

6 years ago Tom was 18 and Sally was 12 which is half Tom's present age.

Book appears to be correct.

Your answer: Tom now 24, Sally now 16

Eight years ago Tom was 16 and Sally was 8 which is half Tom's age THEN, not NOW.