We have 1,2,3,4,5,6,7,8,a,b,c,d,e,f
the numbers and letters are in order. How many permutations
(arrangements) are there...
We have 1,2,3,4,5,6,7,8,a,b,c,d,e,f
the numbers and letters are in order. How many permutations
(arrangements) are there in a way that the order is maintained for
numbers and the order is maintained for letters? Explain.
How many strings of seven lowercase letters from the English
alphabet contain
a. the letters a...
How many strings of seven lowercase letters from the English
alphabet contain
a. the letters a and b in consecutive positions with a preceding
b, with all the letters distinct?
b. the letters a and b, where a is somewhere to the left of b in
the string, with all the letters distinct?