The idea is to compute n C r using below formula. N - r where n represents the number of items and r represents the number of items being chosen at a time. Combinations nCr are the number of combinations of numbers that can be put together where the order that they are selected doesnt matter and numbers are not repeated.
To calculate combinations we will use the formula nCr n.
NCr nr to access the probability menu where you will find the permutations and combinations commands. C Program To Calculate nCr Value. N-r1 r r-1. See the PROB menu in the first screen.