AP EAMCET202021 Sep 2020Evening ShiftMathematicsSequences and SeriesActual
The sum of the cubes of three consecutive natural numbers is divisible by
Options
- A26
- B25
- C9
- D7
Correct answer
C. 9
Step-by-step solution
Let the three consecutive natural numbers ((n-1), n, n+1 ) where (n 2 ) ( ) Sum of cubes of the three consecutive natural numbers is ((n-1)^3+n^3+(n+1)^3=3 n^3+6 n=3 n (n^2+2 ) ) For each value of (n 2 ), the expression (3 n (n^2+2 ) ) is divisible by 9 . Hence, option (c) is correct.