SAT Math Practice Question #26505 - SATify | SATify
#26505
combinatorics
Relative Motion
hard
150 sec
Let S be the set 1,2,3,…,13. For a,b∈S, define a≻b to mean that either 0<a−b≤6 or b−a>6. How many ordered triples (x,y,z) of elements of S have the property that x≻y, y≻z, and z≻x?