A project is completed in 36 days when A and B work together, and in 45 days when B and C work together. Now A, B, and C have worked together for 15 days, and B will complete the rest of the project in 30 days. , Ask B how many days it will take to complete the project alone?
一项工程，甲、乙两人合做，36天完成，乙、丙两人合做，45天完成，现在甲、乙、丙合做15天后，余下的工程再由乙独做30天完成，问乙独做完成这项工程需要多少天？
<gadget id="calculator">1 / 36</gadget>
<output>1/36 = around 0.027778</output>

<gadget id="calculator">(1/36) * 15</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">1 / 45</gadget>
<output>1/45 = around 0.022222</output>

<gadget id="calculator">(1/45) * 15</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (5/12) - (1/3)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">30 - 15</gadget>
<output>15</output>

<gadget id="calculator">(1/4) / 15</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">1 / (1/60)</gadget>
<output>60</output>

<result>60</result>