1.)Amy borrowed $11,149 from her parents to finance a vacation. If simple interest was charged on the loan at 4.21 p.a., how much interest would she have to pay in 180 days?

2.) A loan of $3060 can be repaid in 195days by paying the principal sum borrowed plus $85 interest. What was the rate of interest charged?

3.) Mac's credit card statement included $1059.00 in cash advances and $92.37 in interest charges. The simple interest rate on the statement was 11.25% p.a. For how many days was Mac charged interest?