To solve for percentage you have to first find the percentage's decimal. To find this you have to the move the decimal point up to places. This makes 80 into 0.8. After you do this you will mutiply that but the total amount. So 125 times 0.8. Once you do this you should get 100. This means that Doug sold 100 sandwiches in his neighborhood.
Hmmm if you don't have a Unit Circle, this is a good time to get one, many you can find online. Anyhow, check your unit circle for cos(30°) and sin(30°).
