New Batches at TathaGat Delhi & Noida!               Directions to CP centre
Re: Methods of Summation- Arithmetic Progression, Geometric Progression and Miscellaneous
by Pradeep Kumar - Tuesday, 1 October 2013, 10:12 AM
 

Hi Ankit,

You can group the odd and even (negative and positive respectively) terms separately. It would be of the the form:

(2n) ^ 3 - (2n -1) ^ 3

And here n will be 1,2...8 and not sixteen. Use the sum of cubes formula and you should be able to arrive at the solution.