Answer:
B. 10
Step-by-step explanation:
Let x represent pounds of chocolate worth $1.50 a pound and y represent pounds of chocolate worth 90¢ ($0.90) a pound.
We have been given that a mixture contains 30 pounds of both chocolates. We can represent this information in an equation as:
[tex]x+y=30...(1)[/tex]
We are also told that a mixture of 30 pounds of candy sells for $1.10 a pound. We can represent this information in an equation as:
[tex]1.50x+0.9y=30(1.10)...(2)[/tex]
From equation (1), we will get:
[tex]y=30-x[/tex]
Upon substituting this value in equation (2), we will get:
[tex]1.50x+0.9(30-x)=30(1.10)[/tex]
[tex]1.50x+27-0.9x=33[/tex]
[tex]0.60x+27-27=33-27[/tex]
[tex]0.60x=6[/tex]
[tex]\frac{0.60x}{0.60}=\frac{6}{0.60}[/tex]
[tex]x=10[/tex]
Therefore, 10 pounds of the $1.50 chocolate were used to make the mixture and option B is the correct choice.