If a code word is defined to be a sequence of different letters chosen from the 10 letters A, B, C, D, E, F, G, H, I, and J, what is the ratio of the number of 6-letter code words to the number of 4-letter code words?
Options:
A) 5 to 4
B) 30 to 1
C) 2 to 1
D) 5 to 1
E) 6 to 1
Number of ways to form 6-letter code: 10!/4! = 10*9*8*7*6*5   Number of ways to form 4-letter code: 10!/6! = 10*9*8*7   Ratio: 30 to 1   Answer : 30 to 1
<result>B</result>
If a code word is defined to be a sequence of different letters chosen from the 10 letters A, B, C, D, E, F, G, H, I, and J, what is the ratio of the number of 6-letter code words to the number of 4-letter code words?