Home › CBSE Class 11 (Commerce) › Mathematics › Permutations and Combinations › If nP2 = 90, what is n?
If nP2 = 90, what is n?
A9
B10
C11
D12
Answer & Solution
Correct answer: B. 10
nP2 = n(n - 1) = 90 gives n = 10.
Related questions
Al-Khalil's cryptography book listed words using which idea?A permutation of a finite set is what kind of function on that set?A k-combination of a set S is best described as what?Cauchy's 1815 memoir on substitutions of n elements led to which notion?Which Chinese text used permutation-like hexagrams as early as 1000 BC?How many elements does the symmetric group on 4 objects contain?In how many ways can the letters of BANANA be arranged?A multiset permutation uses each element how many times?