Question

How many arrangements of the 26 letters of the alphabet in which a occurs before b and c occurs before d?

Answer 1

Apply a little logic here. Take letters a and b. You can arrange them as ab and ba, which means 50% of times a is before b. Now take a b and c. You can make 3!=6 arrangements: abc acb bac bca cab cba. In cases abc acb and cab, a occurs before b (it is 50% of the times). No matter if you take all the letters of the alphabet and arrange them in all the possible ways, a will be before b 50% of the times. Same for c and d. And that means that both cases will happen in 25% of the arrangements. Then your solution is: Number of arrangements divided by 4.

And now my question, howmany arrangements can you make with 26 letters?

Answer 2

26!

Answer 3

so the solution is ? (divide by four)

Answer 4

(26!)/4

Answer 5

Yes, have you understood the logic?

Answer 6

Thank you :-)

Answer 7

u r welcome