Question

Clem Colfax had $10 to buy groceries. He needed milk costing 70 cents a carton, bread costing 60 cents a loaf, breakfast cereal costing 50 cents a box, and meat costing $1.50 a pound. He bought twice as many cartons of milk as he did loaves of bread, the number of boxes of cereal was one more than the number of loaves of bread, and the number of pounds of meat was the same as the number of boxes of cereal. How many of each did he buy if the total he spent was exactly $10?

Answer 1

The first thing we must do for this case is to define variables:
 w: pounds of meat
 x: carton of milk
 y: loaf of bread
 z: cereal breakfast box
 We write the system of equations:
 0.70x + 0.60y + 0.50z + 1.50w = 10
 x = 2y
 z = y + 1
 w = z
 Solving the system we have:
 w = 3
 x = 4
 y = 2
 z = 3
 Answer:
 3 pounds of meat
 4 cartons of milk
 2 loaves of bread
 3 boxes of breakfast cereal