Question

A book sold 31,500 copies in its first month of release. Suppose this represents 8.2% of the number of copies sold to date. How many copies have been sold to

date?
Round your answer to the nearest whole number.

Answer 1

to be honest, they have sold "x" copies total, which oddly enough is the 100%, now we also know that 31,500 is 8.2% of "x", hmmm

`\begin{array}{ccll} amount&\%\\ \cline{1-2} x & 100\\ 31500& 8.2 \end{array} \implies \cfrac{x}{31500}~~=~~\cfrac{100}{8.2} \\\\\\ 8.2x=3150000\implies x=\cfrac{3150000}{8.2}\implies x\approx 384146`