Need Mathematics help with sales, gallons and yards

Problem 1: In the following sales report, total the rows and the columns, and then check that the grand total is the same both horizontally and vertically.

Problem 2: Anne Domingoes drives a Volvo that gets 32 miles per gallon. How many miles can she travel on 25 gallons of gas?

Problem 3: Sharon Parker bought 20 yards of material to make curtains. She used 4 ½ yards for one bedroom window, 8 and 3/5 yards for another window, and 3 and 7/8 yards for a hall window. How much material did she have left?

Problem 4: While training for a marathon, Kristin Woods jogged 7 ¾ miles per hour for 2 and 2/3 hours. How many miles did Kristin jog?

Problem 5: On a map, one inch equals 240 miles. How many miles are represented by 3/8 inch?

Problem 6: Leslie Tracy purchased her home for $51,500. She sold it last year for $221,200. What percentage profit did she make on the sale?

Problem 7: Northwest chemical Company received an invoice for $12,480, dated March 12, with terms of 2/10, n/30. If the invoice is paid March 22, what was the amount due?

Problem 8: The cost of an office chair is $159 and the markup rate is 24% of the cost.  What is A. the dollar markup and B. the selling price?

Problem 9: Parker and Company pays Selma Stokes on a variable commission scale. In a month when Selma had net sales of $155,000, what was her Gross Pay based on the following scale?

Problem 10: David Siderski bought a $7,500 bank certificate paying 16% compounded semi-annually. How much money did he get upon cashing in his certificate 3 years later?

Problem 11: Use the Business Math Handbook to find the table factor for each of the following:

Problem 12: You received a $2,000 rebate that brought the price of your car down to $20,000; the financing was for 48 months, and your total interest was $3,279. Using the table in the Business Math Handbook, what was your APR?