Question

R company putchased many tools during 2007 at a total cost of $8,100. Some tools were expected to last a few weeks, some for several months, and some for several years. R companys income for 2007 will be about 4.5 million. How should R company account for the tools in order to be theoretically correct? As a practical matter, how should R company account for these tools? Why?

***I am supposed to indicate the accounting principle or concept that applies***