Here the cost associated with x books is $5 and cost associated with y books is $8.
The total no: of books mentioned is x + y and the total cost associated with it is 5*x + 8*y
Therefore the average cost , in dollars per book is ,
(5*x + 8*y)/(x+y).
Option A is the answer.
The total no: of books mentioned is x + y and the total cost associated with it is 5*x + 8*y
Therefore the average cost , in dollars per book is ,
(5*x + 8*y)/(x+y).
Option A is the answer.
