Question 159824
{{{TotalProfit = SalesCost - PurchaseCost}}}
{{{TotalProfit = 192 - 120 }}}
{{{TotalProfit = 72}}}

{{{ProfitPerLamp * NumberOfLampsSold = TotalProfit}}}
{{{ 6 * NumberOfLampsSold = 72}}}
{{{NumberOfLampsSold = 72/6}}}
{{{NumberOfLampsSold = 12}}}