Zhang Qiang bought some rice paper to practice brush calligraphy. In the first month, he used 3/8 of the total. In the second month, he used 15 sheets less than the first month. It is 5:3. How many pieces of rice paper did Zhang Qiang buy in total?
张强买了一些宣纸练习毛笔字，第一个月用了总数的(3/8)，第二个月比第一个月少用了15张，这时用去的与剩下的张数比是5：3，张强一共买了多少张宣纸？
<gadget id="calculator">15 * 5</gadget>
<output>75</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<gadget id="calculator">75 + 45</gadget>
<output>120</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(3/8) * 5</gadget>
<output>15/8 = around 1.875</output>

<gadget id="calculator">(3/8) * 3</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">3 - 5 - 3</gadget>
<output>-5</output>

<gadget id="calculator">(15/8) + (9/8) + (15/8) + (9/8) + (-5)</gadget>
<output>1</output>

<gadget id="calculator">120 / 1</gadget>
<output>120</output>

<result>120</result>