If the difference between the two commercial and valid interest for an amount at a :certain rate and for a period is 9 dinars, then the valid interest is Select one: O a. 648 dinars O b. 652 dinars O c. 654 dinars O d. 650 dinars If the loan is 4,500 dinars at a rate of 8.5% annually with simple :interest for a period of 200 days, then the interest Select one: O a. 216.5 dinars O b. 212.5 dinars O c. 214.5 dinars O d. 218.5 dinars