Intrest rate for part (A) is 20%. Please elaberate on explanation. Thank you!

Securing the best savings interest rates can mean the difference between earning $200 or $10 in a year. Annual percentage yields, or APYs, of the best savings accounts are significantly higher than the national average of 0.09%, so you can grow your money faster without much effort on your part. by Research to see if the interest rate you calculated in part TTT Art 312T is possible. Cite your sources E- Pata