An insurance firm has offered an educational plan where it promised to make single payment of ₱500,000 eight years from now in exchange for an initial investment of only ₱100,000. What rate of return...

 An insurance firm has offered an educational plan where it promised to make single payment of ₱500,000 eight years from now in exchange for an initial investment of only ₱100,000. What rate of return is the firm promising for this offer 8 years from now?