Question
Mathematics Question on permutations and combinations
If n+1Cr+1: nCr: n-1Cr-1 = 55: 35: 21 then the value of n + r is _____.
Answer
The correct answer is 16.
If n+1Cr+1: nCr: n-1Cr-1 = 55: 35: 21 then the value of n + r is _____.
The correct answer is 16.