Question

A wholesaler buys plastic lamps for $18 each and sells them for $30.60. What is the percent markup based on cost?

Answer 1

\(\large \begin{array}{ccllll}
value&\%
\\\hline\\
18&100\\
30.60-18\quad &x
\end{array}\implies \cfrac{18}{30.60-18}=\cfrac{100}{x}\)

Answer 2

Markup based on cost. (30.60-18.00)/18.00
Markup based on retail price. (30.60-18.00)/30.60

Be very careful to notice which is wanted. If it is not specified, you must pick. Very nicely, this problem specifies clearly!!