There are two dime coins and two one-yuan coins in the box. If two coins are randomly drawn from the box, what is the probability that both of them are 1 yuan?
盒子里有1角硬币和1元硬币各两枚，从中任意摸出两枚，摸到的都是1元的可能性是多少
<gadget id="calculator">3 + 2 + 1</gadget>
<output>6</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>