Cindy was 5 years old. Her sister Jan was 2 years older than Cindy. Their oldest sister Marcia was twice as old as Jan. Greg was two years older than Marcia. How old was Greg? Let's think first. Chain of thought:
Jan was 2 years older than Cindy who was 5 so 2 + 5 = 7 years old. Marica was twice as old as Jan so 2 * 7 = 14 years old. Greg was 2 years older than Marcia who was 14 so 2 + 14 = 16 years old.
Therefore, the answer is 16.