What amount of money invested today at 15 % interest can provide the following scholoarships: Php 30,000 at the end of each year for 6 years, Php 40,000 for the next 6 years and Php50, 000 thereafter?...

What amount of money invested today at 15 % interest can provide the following scholoarships: Php 30,000 at the end of each year for 6 years, Php 40,000 for the next 6 years and Php50, 000 thereafter?

What would be the formula for this question and the cashflow diagram?