Xiao Lin went shopping in the mall, and spent 45% of the total money on school supplies, and 25% of the total money on food. It cost 20 yuan more to buy school supplies than to buy food. How much did Xiao Lin bring in total?
小林去商场购物，买学习用品花了总钱数的45%，买食品用去总钱数的25%，买学习用品比买食品多花20元，小林一共带了多少钱？
<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(9/20) - (1/4)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 / (1/5)</gadget>
<output>100</output>

<result>100</result>