A printing factory binds a batch of homework books. If all employees work at the same time, each person needs to bind 48 books on average. If only male employees are allowed to bind, each person needs to bind 120 books on average; if only female employees are required to bind, how many books should be bound on average Book.
印刷厂装订一批作业本，如果全体职工同时干，平均每人要装订48本，如果只让男职工装订，平均每人需装订120本；如果只让女职工装订，平均每人应装订多少本．
<gadget id="calculator">1 / 48</gadget>
<output>1/48 = around 0.020833</output>

<gadget id="calculator">1 / 120</gadget>
<output>1/120 = around 0.008333</output>

<gadget id="calculator">(1/48) - (1/120)</gadget>
<output>1/80 = around 0.0125</output>

<gadget id="calculator">1 / (1/80)</gadget>
<output>80</output>

<result>80</result>