Answer- A) 59,600 ; B) 4.12% per year.
Step-by-step explanation
84,200 minus 24,600 is 59,600. This means the originally cost put into the account was 59,600.
Next we have to divide the amount of interest earn into the number of years that the amount was accumulated. 24,600 divided by 10 is 2460. This means that each year 2,460 were earned in interest. 59,600 divided into 2,460 is 0.0412751678. This rounds to .0412 If we move our decimal to a percentage this leaves us with 4.12% This means that annual interest on the investment is 4.12%
Hope this helps! Good Luck!