MathCastle
Number TheoryChallengeHard Number Theory

Hard Number Theory · Challenge problem

Evaluate ∑k=116(⌊7k17⌋+⌊10k17⌋)\displaystyle\sum_{k=1}^{16}\left(\left\lfloor \frac{7k}{17} \right\rfloor + \left\lfloor \frac{10k}{17} \right\rfloor\right).