On the day his son was born, a father deposited to a trust company a sufficient amount of money so that his son could receive money in the future. There was a provision that the son can withdraw an...

On the day his son was born, a father deposited to a trust company a sufficient amount of money so that his son could receive money in the future. There was a provision that the son can withdraw an amount of P10,000 each year for 3 years starting on his 18th birthday and P15,000 eight months after the last withdrawal. The interest rate is 5% compounded monthly.

1. What is the effective interest rate?

2. How much did the father deposit?

3. How much money can he receive on his 18th birthday, if he decided to withdraw all the money at once?