[Solved] CSC 225 Assignment 1-Algorithms and data structures

1a. How many arrangements are there of all the letters in INDIVIDUAL?

1b. How many arrangements of the letters in INDIVIDUAL have all three Is adjacent?

1c. How many arrangements of the letters in INDIVIDUAL have no Is adjacent?

2. Suppose that you draw five cards from a standard deck of 52.
   1. How many ways can you draw exactly 2 hearts?
   2. How many ways can you draw at most 2 hearts?
   3. How many ways can you draw exactly 2 hearts and 3 clubs?
3. Determine the coefficient of x⁸y⁷ in the following expansions:
   1. (x + y)¹⁵
   2. (-3x + y)¹⁵
   3. (10x 2y)¹⁵
4. Determine the number of integer solutions of x₁ + x₂ + x₃ + x₄ = 17, where a. x_i 0, 1 i 4
   1. x₁, x₂ 3 and x₃, x₄ 1
   2. x_i -2, 1 i 4
   3. x₁, x₂, x₃ > 0 and 0 < x₄ 10
5. Prove that if we select 101 integers from the set S = {1, 2, 3, . . . , 200}, there exist m, n in the selection where the greatest common divisor of m and n is 1. Hint: Prove by the Pigeonhole Principle