Help me with 2,3,4,5,6 and show me how you get it and the answers

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

Jim had 3,067.48 in his checking account he wrote a check to pay for two airplane tickets. his account now has 1,845.24.

Ana earns 2.5% simple interest on $2,000 in her savings account. she does not make any deposits or withdrawals. after 3 years, how much interest will ana have earned on her savings account?