Ok so here first lets find out how much that it would cost Rico to buy 5 notebooks, to find this first we need to find the unit price of each of these, this can be found by taking the price divided by the amount that they bought or are selling to you. So we take 7/4=1.75 then 2.5/10=.25, so we now know that it costs $1.75 for one notebook and $0.25 for one folder. Now to find are end answer just multiply these unit prices by the amount that he needs like this, 1.75*5=8.75, and .25*6=1.5. So are end answer is that it will cost Rico $8.75 for 5 notebooks and $1.50 for 6 folders, or 8.75+1.5=10.25, so it will cost him in total $10.25 for 5 notebooks and 6 folders.
Enjoy!=)
