How would i figure out the answer of my assignment

What is the compound interest in a three-year, $100,000 loan at a 10 percent annual interest rate a) 10.00 b) 21.00 c) 33.10 d) 46.41

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?

Write an algebraic expression to match each statement a. four less than 8 times a number b. twice the difference of a number and six c. nine from a number squared