When Mr. Desrosiers was younger, he collected Superman comic books and would save his allowance money to purchase more comic boo
ks. At the end of the first month, he purchased two comic books. At the end of the second month, he purchased five more comic books. At the end of the third month, he purchased eight more comic books. Assuming this pattern continues, how many comic books will he have collected by the end of the year (the 12th month)?
