The maintenance margin is $30\%.$ Ben purchases $$40,000$ worth of IBM stocks. He pays

$$24,000$ cash and borrows $$16,000$ from his broker. The broker charges $5\%$ annual interest rate

on the call loan. $(20$ points$)$

$($a$)$ What is the margin on his account?

$($b$)$ One year later, the value of IBM stocks increases to $$50,000.$ Will Ben receive a margin call

or not?

$($c$)$ What is the net rate of return on the investment?