A) This problem involves 8-digit binary strings such as 10011011 or 00001010.

i How many such strings are there?

ii. How many such strings end in 0?

iii. How many such strings have l's for their second and fourth digits?

iv. How many such strings have l's for their second or fourth digits?

b) Find how many 9-digit numbers can be made from the digits 1, 2, 3, 4, 5, 6,

7, 8, 9 if repetition is not allowed and all the odd digits occur first (on the

left) followed by all the even digits.

c) How many permutations of the letters A, B, C, D, E, F, G are there in which

the three letters ABC appear consecutively, in alphabetical order?