There are 12 black balls and white balls in the black box. To make the probability of touching the black ball greater than (1/4), how many black balls should there be in the pocket at least.
黑色盒子中有黑球和白球共12个，要使摸到黑球的可能性大于(1/4)，口袋中至少应该有多少个黑球．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">12 * (1/4)</gadget>
<output>3</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<result>4</result>