How do you fnd the total amount of an interest paid? The question is "Find the total amount of interest paid one a principal of $2600 at a rate of 12% calculated per annum over 3 years." and I'm not sure how to figure it out

You are choosing between two health clubs. club a offers membership for a fee of $ 28 plus a monthly fee of $ 20. club b offers membership for a fee of $ 20 plus a monthly fee of $ 22. after how many months will the total cost of each health club be the same? what will be the total cost for each club? in __ months the total cost of each health club will be the same.