Just need help with this part, please (originally was 3 parts, this is only 1 part that I need help on).

Iron Man has been offered an investment that will pay him $250,000 per year starting on his 35th birthday and continuing until his 60th birthday (his last payment of $250,000 will occur on his 60th birthday). He then will receive $40,000 every six months, with the first of these coming six months after his last payment of $250,000 and continuing until his 80th birthday (that will be his last payment of $40,000). Finally, he will receive $24,000,000 one year after his last payment of $40,000. Assuming each is celebrating their 28th birthday today and they have a 7% (semi-annual) opportunity cost, which of them has the best offer? SHOW ALL WORK as presented in lectures and solutions. Make your decision using the present value concept