There are 6 pencils in a bag, and if one is picked at random, the probability of getting a red pencil is (1/3). If you want to reduce the probability of getting a red pencil to (1/4), how many more non-red pencils can you put in the bag.
一只袋子中装有6支铅笔，从中任取一支，拿到红色铅笔的可能性是(1/3)．如果要想使拿到红色铅笔的可能性变成(1/4)，可以在袋子中再放入多少枝非红色铅笔．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">6 * (1/3) * 3</gadget>
<output>6</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">6 * (2/3)</gadget>
<output>4</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<result>2</result>