MathDB
2000 Guts #11: Maximum value

Source:

October 12, 2014

Problem Statement

Let MM be the maximum possible value of x1x2+x2x3++x5x1x_1x_2+x_2x_3+\cdots +x_5x_1 where x1,x2,x5x_1, x_2, \cdots x_5 is a permutation of (1,2,3,4,5)(1,2,3,4,5) and let NN be the number of permutations for which this maximum is attained. Evaluate M+NM+N.