If 1 1 1 1=R, and 2 2 2 2=T, and 3 3 3 3=E, and 4 4 4 4=N, then what will 5 5 5 5=? What is the following expression evaluate to? ([math]1 / (2 * 3 * 4)) + (1 / (3 * 4 * 5)) + (1 / (4 * 5 * 6)) + ... + (1 / ((n-2) * (n-1) * n))[/math]