A company sells cardboard that is 9 1/4mm thick. Write an equation to solve for the number of sheets of cardboard, c, in a pile that is 129 1/2mm thick. What must be done to both sides to solve the equation?

Question

sburchette · Answer

We can let c equal the number of sheets of cardboard in the pile.  The total thickness of a pile of sheets will be the thickness of one sheet multiplied by the numbers sheets you have.  So the general equation for this problem is$$T=9.25c$$ Where T is the total thickness and c is the numbers sheets you have. The problem has told us that the total thickness is 129.5.  So now our equation is $$129.5=9.25c$$ To solve for c, simply divide each side of the equation by 9.25 which will give you $$c=14$$ So there are 14 sheets of cardboard in the pile.