Among the 20 footballs numbered 1 to 20, Xiao Ming randomly takes a football from it, so what is the probability that the football number Xiao Ming gets is an integer multiple of 3?
在编号为1到20的20个足球中，小明从中任意拿走一个足球，那么小明拿到的足球编号为3的整数倍的可能性大小为多少．
<gadget id="calculator">6 / 20</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>