Answer:
11,200
Step-by-step explanation:
Account opened: August 1st, with $400.
1 yr : 400+600= $1000 2 years old: 1000+600= $1600 3 years old: 1600+600=$2200 4 years old:2200+600=$2800 5 years old: 2800+600=$3400 6 years old:3400+600=$4000 7 years old:4000+600=$4600 8 years old:4600+600=$5200: 9 years old:5200+600=$5800 10 years old:5800+600=$6400 11 years old:6400+600= $7000 12 years old:7000+600= $7600 13 years old:7600+600=$8200 14 years old:8200+600=$8800 15 years old:8800+600=$9400 16 years old:9400+600= $10,000 17 years old:10,000+600=10,600 18 years old:+600=11,200
