Question 9
Permutation and CombinationFor what value of n is n+1C3 = 4(nC3)?
- A.6
- B.5
- C.4
- D.3
Show the answer and explanation
Answer: D (3)
Explanation
n+1C3/nC3 = (n + 1)/(n − 2) = 4, so n + 1 = 4n − 8 and n = 3.
For what value of n is n+1C3 = 4(nC3)?
Answer: D (3)
n+1C3/nC3 = (n + 1)/(n − 2) = 4, so n + 1 = 4n − 8 and n = 3.