Astore sells brazilian coffee for $10 per lb. and columbian coffee for $14 per lb. if the store decides to make a 150-lb. blend of the two and sell it for $11 per lb., how much of each type of coffee should be used?

The store should use 112.5 pounds of Brazilian coffee and 37.5 pounds of Colombian cofee.

Step-by-step explanation:

Let "b" be the amount of Brazilian coffee, in pounds, required for the blend and "c" the amount of Colombian coffee required, in pounds.

Since there are two unknown variables a two-equation system is needed to solve the problem, we can set up one equation for weight and another for price as follows:

Solve for "c" by multiplying the first equation by -10 and adding it to the second one:

Now, solve for b by replacing the value obtained into the first equation

The store should use 112.5 pounds of Brazilian coffee and 37.5 pounds of Colombian cofee.