Peter is at a lumber yard. He gets 2 free boxes of nails for every 10 boards he buys. Write an expression for the number of boxes of nails Peter will get if he buys n boards. If each box has 100 nails, explain how to write an expression to find how many nails Peter will have if he purchases 90 boards.

Accepted Solution

a. The number of 10-boards Peter bought is equal to n divided by 10. Then, each of the 10-boxes will get two boxes of nails. The number of boxes of nails that Peter will have after buying n boards will be,

    N = (2)(n/10)


   N = n/5

b. If the number of boards are 90 then,

     N2 = (90/10)(2)(100 nails/box)
     N2 = 1800

Answer: 1800