iran-konkur 2016 Q143

iran-konkur · Other · konkur-riazi_1395_specialized Proof by induction Prove a summation identity by induction
143. We know that the sum of cubes of consecutive odd numbers starting from 1 equals the square of the sum of those numbers. What is the sum of cubes of consecutive odd numbers starting from 1 and ending at 19?
(1) $18800$ (2) $18900$ (3) $19800$ (4) $19900$
\textbf{143.} We know that the sum of cubes of consecutive odd numbers starting from 1 equals the square of the sum of those numbers. What is the sum of cubes of consecutive odd numbers starting from 1 and ending at 19?

(1) $18800$ \quad (2) $18900$ \quad (3) $19800$ \quad (4) $19900$