A book has 200 pages. Xiaohong reads (2/5) of the whole book on the first day and (1/5) of the whole book on the second day. How many pages should she read from on the third day?
一本书200页，小红第一天看了全书的(2/5)，第二天看了全书的(1/5)，第三天应从第多少页看起．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/5) + (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">200 * (3/5)</gadget>
<output>120</output>

<gadget id="calculator">120 + 1</gadget>
<output>121</output>

<result>121</result>