For many years, a state used 3 letters followed by 3 digits on its automobile license plates. Complete parts (a) through (c) below. (a) How many different license plates are possible with this arrangement? Use scientific notation. Use the multiplication symbol in the math palette as needed. Round to three decimal places as needed.) (b) When the state ran out of new numbers, the order was reversed to 3 digits followed by 3 letters. How many new license plate numbers were then possible? (Use scientific notation. Use the multiplication symbol in the math palette as needed. Round to three decimal places as needed.) (c) Eventually, the numbers described in part (b) were also used up. The state then issued plates with 1 letter followed by 3 letters and then 3 digits. How many new license plate numbers will this provide? (Use scientific notation. Use the multiplication symbol in the math palette as needed. Round to three decimal places as needed.)