A certain project can be completed by A alone for 48 days, and then by B alone for 30 days; if A and B work together, it will take 40 days to complete. Now A works alone for 24 days, and then B alone completes it , Ask B how many days to do?
某工程先由甲单独做48天，再由乙单独做30天，即可完成；如果由甲、乙合做则需40天完成，现在甲先单独做24天，然后再由乙来单独完成，问乙还要做几天？
<gadget id="calculator">1 / 40</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">48 - 30</gadget>
<output>18</output>

<gadget id="calculator">(1/40) * 30</gadget>
<output>3/4 = around 0.75</output>

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

<gadget id="calculator">18 / (1/4)</gadget>
<output>72</output>

<gadget id="calculator">1 / 72</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">(1/40) - (1/72)</gadget>
<output>1/90 = around 0.011111</output>

<gadget id="calculator">1 / (1/90)</gadget>
<output>90</output>

<gadget id="calculator">(1/72) * 24</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">90 * (2/3)</gadget>
<output>60</output>

<result>60</result>