It is known that (1/4) of a is equal to (1/5) of b, a is 20, what is b
已知a的(1/4)等于b的(1/5)，a为20，b为多少
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) / (1/5)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">20 * (5/4)</gadget>
<output>25</output>

<result>25</result>