The school bought 147 science and technology books, and (3/5) of literature and art books is equal to (4/7) of science and technology books. How many literature and art books are there?
学校买来科技书147本，文艺书的(3/5)等于科技书的(4/7)，文艺书有多少本？
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(4/7) / (3/5)</gadget>
<output>20/21 = around 0.952381</output>

<gadget id="calculator">147 * (20/21)</gadget>
<output>140</output>

<result>140</result>