I was doing the timed quant hard sample test 3 and saw the video solution for 2 tough combinatorics questions. I wanted to share a shorter solution from my side in case it’s useful for folks.
1. Jack has 8 marbles in four colors, with two marbles of each color. He wants to group his marbles into four pairs such that no pair consists of marbles of the same color. What is the number of ways he can do this?
2. In how many different ways can the letters in the word GREGMAT be ordered such that neither the first letter nor the last are vowels?
