pleSe help

Rob has just received a check for $31,000. This is a return from an investment that he made 19 years ago. He was told that the return was the equivalent of 11% per year. How much was his original investment? $3,901.19. $4,055.52. $4,268.01. $4,006.25. Question 4 6.25pts Jasn received a check for $50,000 today. This was from an investment made 10 years ago. The investment earned 10% compounded quarterly. How much was his original investment? $18,621.53. $13,795.06. $10,101.90. $24,90,97. Question 5 Tony saved enough money to place $125,500 in an investment generating 9.5% compounded monthly. He wants to collect a monthly income of $1,350, at the beginning of each month, for as long as the money lasts. How many months will Tony have this income coming to him? 161 166 170