At the farmer's market, Joan bought apples at $1.20 per pound, cherries for $2.00 per pound and pears for $0.80 per pound. She bought a total of 11 pounds of fruit for $9.00. Joan bought twice as
many pounds of apples than cherries.
Let A be the weight of the apples, C be the weight of the cherries, and P be the weight of the pears.
Formulate a system of equations to determine how many pounds of each type of fruit were bought.