I need assistance solving these few college math problems. Please show your work so that I can better understand how to solve the problem. Thank you!

5. Write each fraction in simplest form.

a.50/75

b.105/120

14. Find the unknown number n in each proportion.

a.n = 18

b.n =2

19. Solve. Round all dollar amounts to the nearest cent.

a.A cleaning solution has 40% vinegar. Find the amount of vinegar in 32 ounces of the solution.

b.If the sales tax is 7.12%, find the total amount charged for a lamp priced at $60.

20. Solve. Round all dollar amounts to the nearest cent.

a.Marty borrowed $450 at 9% interest for 3 months. Find the total amount due at the end of the 3 months.

b.$5000 is compounded quarterly at a rate of 10%. Find the total amount in the compound interest account at the end of 20 years. (The compound interest factor is 7.20957).