Among (8/15), (9/36) and (3/12), how many numbers cannot be reduced to finite decimals?
(8/15)、(9/36)、(3/12)中，不能化成有限小数的是多少．
<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>