Among the simplest proper fractions whose denominator is less than 50, what is the fraction whose value is closest to (3/7).
在分母小于50的最简真分数中，分数值最接近(3/7)的是多少．
<gadget id="calculator">20 / 49</gadget>
<output>20/49 = around 0.408163</output>

<result>20/49 = around 0.408163</result>