The teacher distributes some books to five students A, B, C, D, and E. Give half of it to A first, then give the rest (1/4) to B, and then give the rest (1/3) to C, and finally give D 2 copies less than E, and E is 40% more than D ． Then how many books did the teacher have?
老师把一些书分给A，B，C，D，E五个学生．先将其中一半给A，再把剩下的(1/4)给B，再把余下的(1/3)给C，最后给D比给E的少2本，且E比D多40%．则老师原有多少本书．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2 / (2/5)</gadget>
<output>5</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">5 + 7</gadget>
<output>12</output>

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

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

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">12 / (2/3) / (3/4) / (1/2)</gadget>
<output>48</output>

<result>48</result>