A store has several red balloons and yellow balloons, and the number of red balloons is 4 times that of yellow balloons. Sell 2 red balloons and 1 yellow balloon every day. A few days later, there were 12 red balloons left, and the yellow balloons were just sold out. How many red balloons were there?
某商店有红气球和黄气球若干个，红气球的个数是黄气球的4倍．每天卖出2个红气球和1个黄气球．若干天后，红气球剩下12个，黄气球刚好卖完．红气球原来有多少个？
<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">2 * 6</gadget>
<output>12</output>

<gadget id="calculator">12 + 12</gadget>
<output>24</output>

<result>24</result>