Can someone solve this?
I have done part (a).
Need help with (b)and(c)

Ricky takes out a $31,800 student loan to pay his expenses while he is in college. after graduation, he will begin making payments of $190.66 per month for the next 30 years to pay off the loan. how much more will ricky end up paying for the loan than the original value of $31,800? ricky will end up paying $ more than he borrowed to pay off the loan.

|z| > (1/2) {-1/2, 1/2} {z|(-1/2) < z < (1/2)} {z|z < (-1/2) ∪ z > (1/2)}

On tuesday, a local hamburger shop sold a combined total of 375 hamburgers and cheeseburgers. the number of cheeseburgers sold was two times the number of hamburgers sold. how many hamburgers were sold on tuesday?