There are 80 bags of cement and 183 bags of sand on the construction site. From the first day, 8 bags of cement are used every day, and 7 bags of sand are used every day. After a few days, the number of bags left with sand is 15 times that of cement.
工地上有水泥80袋，沙子183袋，水泥从第一天起每天用8袋，沙子每天用7袋，多少天以后沙子剩下的袋数是水泥的15倍．
<gadget id="calculator">80 * 15</gadget>
<output>1_200</output>

<gadget id="calculator">1_200 - 183</gadget>
<output>1_017</output>

<gadget id="calculator">8 * 15</gadget>
<output>120</output>

<gadget id="calculator">120 - 7</gadget>
<output>113</output>

<gadget id="calculator">1_017 / 113</gadget>
<output>9</output>

<result>9</result>