The manager of a coffee shop has one type of coffee that sel

The manager of a coffee shop has one type of coffee that sells for $9 per pound and another type that sells for $14 per pound. The manager wishes to mix 30 pounds of the $14 coffee to get a mixture that will sell for $11 per pound. How many pounds of the $9 coffee should be used?

Solution

Let x pounds of $9 coffee

Let y pounds of $14 coffee

y = 30 pounds (given)

(9x + 30*14) /(x+30) = $11

(9x + 420) = 11x + 330

2x = 90

x = 45 pounds of $9 coffee