The sum of all 3-digit numbers less than or equal to 500 , that aren formed without using the digit " 1 " and they all are multiple of 11 ,n is

S = (209 + 220 + 231 + ... + 495)n nn- (231 + 319 + 418 + 341 + 451)nn= (27 / 2) x 704 - 1760 = 9504 - 1760 = 7744n

The sum of all 3-digit numbers less than or equal to 5... | Sequence & Series (Mathematics)

S = (209 + 220 + 231 + \ldots + 495)

\n\end{enumerate}\n\n

- (231 + 319 + 418 + 341 + 451)

\n\n

= \frac{27}{2} \times 704 - 1760 = 9504 - 1760 = 7744