Q14: If a code word is defined to be a sequenceof different letters chosen from the 10 letters A, B, C, D,E, F, G, H, I, and J, what is theratio of the number of 5-letter code words to the number of 4-letter codewords?
A. 5 to 4 B. 3 to 2 C. 2 to 1 D. 5 to 1 E. 6 to 1 这题不太知道在问什么,在sequence这点卡住, 是任意排列还是要照顺序的ex. ABCDE. CDEFG?? 麻煩各位NN們