2024 · Q21
The arithmetic mean of n numbers is M. If the sum of first (n - 1) terms is k, then what is the n^(th) number?
Elementary MathematicsStatistics
- AM - k
- BnM - k
- Cn(M - k)
- DM - nk
Explanation
The sum of all n numbers is n×M = nM. Subtracting the sum k of the first n−1 terms leaves the nth number = nM − k. This is option B.