what is 10.5%of 515000 for 90 days
I assume you are asking what is the interest on $515,000 over a period of 90 days using simple interest at 10.5% APR
For 1 yr (365 days), this would be (10.5/100)*(515,000) = 54,075
For 90 days, the fraction value of the annual interest is (90/365)*(54,075) = 13,333.56
Answer: $13,333.56