Answer:
try " 15"
Step-by-step explanation:
Option A
The system of equations are x + y = 40 and 10x + 7y = 360
<em><u>Solution:</u></em>
Let pounds of expensive coffee beans be x
Let pounds of cheaper coffee bean be y
Cost of 1 pound of expensive coffee bean = $ 10
Cost of 1 pound of cheaper coffee bean = $ 7
<em><u>The shop also sells a 40 pound mixture of the two kinds of coffee beans</u></em>
pounds of expensive coffee beans + pounds of cheaper coffee bean = 40
x + y = 40 ------ eqn 1
<em><u>The shop also sells a 40 pound mixture of the two kinds of coffee beans for $9 per pound</u></em>
pounds of expensive coffee beans x Cost of 1 pound of expensive coffee bean + pounds of cheaper coffee bean x Cost of 1 pound of cheaper coffee bean = 40 pound mixture x $ 9
10x + 7y = 360 --------- eqn 2
Thus the system of equations are x + y = 40 and 10x + 7y = 360
Thus option A is correct