A credit card number has 6 digits (between 1 to 9 inclusive). The first two digits are 12 in that order, the third digit is bigger than 6, the fourth digit is divisible by 3, and the fifth digit is 2 times the sixth. How many different credit card numbers are possible? Choose the correct choice from the following:
A) 18  B) 24  C) 36  D) 48  E) 72
The first two digits are fixed.   The third digit can be 7, 8, or 9 so there are 3 choices.   The fourth digit can be 3, 6, or 9 so there are 3 choices.   The fifth digit depends entirely on the sixth digit.   The sixth digit can be 1, 2, 3, or 4 so there are 4 choices.   The number of possibilities is  3*3*4= 
<gadget id="calculator"> 3*3*4</gadget>
<output>36</output>
36   The answer is 36.
<result>C</result>
A credit card number has 6 digits (between 1 to 9 inclusive). The first two digits are 12 in that order, the third digit is bigger than 6, the fourth digit is divisible by 3, and the fifth digit is 2 times the sixth. How many different credit card numbers are possible?