Question:medium

The sum of the infinite series \( \frac{1}{5} \left( \frac{1}{5} - \frac{1}{7} \right) + \left( \frac{1}{5} \right)^2 \left( \frac{1}{5} - \frac{1}{7} \right)^2 - \left( \frac{1}{7} \right)^2 + \left( \frac{1}{5} \right)^3 \left( \frac{1}{5} - \frac{1}{7} \right)^3 + \dots \) is equal to

Updated On: Nov 24, 2025
  • \(\frac{7}{408}\)
  • \(\frac{5}{408}\)
  • \(\frac{7}{816}\)
  • \(\frac{5}{816}\)