How do I go about solving these 4 questions? The red is the correct answers but how do I get to that point? Thanks in advance!

12. An investment is expected to produce cash flows of 300, 770, -600, and $150 dollars at the end of the next four years. If the required rate of return is 3.2%, the present value of this investment is closest to A) $600 B) $700 C) $800 D) $900 13. Jacob is looking at a $325,000 home. If 20% must be put down and the balance is financed at 6.94% over the next 30 years, what is the monthly mortgage payment? A) $1,123.97 B) $1,365.51 C) $1,517.44 D) $1,719.32 14. A given quoted as 12.85% nominal interest rate and has an EAR of 13.26%. What is the compounding frequency during the year? A) Weekly B) Monthly C) Quarterly D) Semiannually 15. Lori estimates that Microsoft's earnings will grow from $18.95 a share to $244.85 per share over the next 9.25 years. The rate of growth in Microsoft's earnings is closest to A) 15.85%. B) 25.00%. C) 31.87%. D) 51.95%