Hi , im stuck in this question . Can i please get an answer ? which formula am i supposed to use ? what is the answers ? Thank you

Question 8

Nabil has a balance of $3,000 on his credit card. Assume he only makes the minimum required payment of $90 on this balance every month until the card is paid off. Assume also that no new purchases are made with this card. The interest rate charged on the card is 18% per annum, compounded daily. How much total interest will he have paid on his card by the time the $3,000 is fully paid off?

a)     $1,654.33

b)     $1,490.20

c)     $1,203.80

d)     $1,200.41

Question 10

Xavier borrowed $492,000 to finance the purchase of a home. His mortgage amortization was 25 years at a rate of 4%, compounded semi-annually. Payments are made monthly. If Xavier increases his monthly mortgage payment by 10% and holds them at level, how much quicker can he pay his mortgage down?

a)     43.34 months

b)     56.99 months

c)     61.00 months

d)     75.00 months