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 5-letter code words? Select
A) 5 to 4  B) 3 to 2  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 5-letter code: 10!/5! = 10*9*8*7*6   Ratio: 5 to 1   Answer : 5 to 1
<result>D</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 5-letter code words?