A certain stock exchange designates each stock with a two-letter or three-letter code, where each letter is selected from the 26 letters of the alphabet. If the letters may be repeated and if the same letters used in a different order constitute a different code, how many different stocks is it possible to uniquely designate with these codes without using the vowels A, E, I, O, or U?
Choose the correct choice from the following.
A) 9372
B) 9482
C) 9592
D) 9702
E) 9812
The number of two-letter codes is  21*21= 
<gadget id="calculator"> 21*21</gadget>
<output>441</output>
441.   The number of three-letter codes is  21*21*21= 
<gadget id="calculator"> 21*21*21</gadget>
<output>9_261</output>
9261.   The total number of codes is   441+9261= 
<gadget id="calculator">  441+9261</gadget>
<output>9_702</output>
9702.   The answer is 9702.
<result>D</result>
A certain stock exchange designates each stock with a two-letter or three-letter code, where each letter is selected from the 26 letters of the alphabet. If the letters may be repeated and if the same letters used in a different order constitute a different code, how many different stocks is it possible to uniquely designate with these codes without using the vowels A, E, I, O, or U?