1. Alana will have in her account:$2,232.05 after 21 days. So, the interest she earns is:$2,232.05 - $2,225.00=$7.05
2.Dell will have a total of: $173,074.25 after 12 years. Dell will have earned:$173,074.25 - [$1,000 X 144]=$29,074.25 in interest.
3.Oscar's account will have a total of:$7,418.65 after 2 quarters.