NPr nrn nr3P23 32 3216 ways. I noticed that the powers on each term in the expansion always added up to whatever n was and that the terms counted up from zero to nReturning to our intial example of 3x 2 10 the powers on every term of the expansion will add up to 10 and the powers on the terms will increment by. How many different combinations are there.
More formally the number of k-element subsets or k-combinations of an n-element set.
So some of the permutations would be ABC ACB BAC BCA CAB and CBA. From the above formulas follow relations between adjacent numbers in Pascals triangle in all three directions. It is the number of items chosen from the sample. AB BA AC CA BC CB 6 ways persons can sit on that seats.