Question

How

manyfour character codes can be generated if the first character
mustbe a letter, the next two letters must be numbers, and the
lastcharacter must be a 1, 3, or 7?

Answer 1

Answer: 7800

Explanation:

As English alphabet has 26 letters.

So , Choices for First character in the code = 26

The choices for digits = 10 (From 0 to 9)

So , choices for second character = 10 (Middle two characters must be numbers)

choices for third character = 10 (Middle two characters must be numbers)

Choices for last character = 3 (the last character must be a 1, 3, or 7)

By Fundamental principle of counting , the total number of four character codes can be generated =

(Choices for First character)x (choices for digits) x(choices for digits) x(Choices for last character)

= (26) (10)(10)(3) =7800

Hence, the total number of character codes can be generated= 7800