After one year it earns $10 in interest because 100 x .1 = <<100*.1=10>>10
It has $120 in it after a year because 100 + 10 + 10 = <<100+10+10=120>>120
In the second year it earns $12 in interest because 120 x .1 = <<120*.1=12>>12
In the second year it has $142 in it because 120 + 12 + 10 = <<120+12+10=142>>142
#### 142