Mandy started reading books with only 8 pages when she was 6 years old. By the time she was twice that age, she was reading books 5 times longer, and 8 years later, she was reading books 3 times longer than that. Presently, she reads books that are 4 times the previous length. How many pages do the books she reads now have? Let's answer step by step:
Twice the age of 6 is 6 x 2 = 12 years old. At 12 years old, Mandy was reading books 5 x 8 = 40 pages long. 8 years later, Mandy was 12 + 8 = 20 years old. At 20 years old, Mandy was reading books 3 x 40 = 120 pages long. Presently, she reads books that are 120 x 4 = 480 pages long. The answer: 480.