Among (5/6), (2/5) and (5/18), how many can be reduced to finite decimals?
在(5/6)、(2/5)和(5/18)中，能化成有限小数的有多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>