There are several grapefruits and watermelons in the store, and the number of watermelons is three times the number of grapefruits. If 30 watermelons and 20 grapefruits are sold every day, after 3 days, the number of watermelons will be 4 times less than the number of grapefruits 26. Then how many grapefruits are there in the store?
商店里有若干个柚子和西瓜，其中西瓜个数是柚子个数的3倍．如果每天卖出30个西瓜和20个柚子，3天后，西瓜个数比柚子个数的4倍少26．则商店里原有多少个柚子．
<gadget id="calculator">20 * 3 * 4</gadget>
<output>240</output>

<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<gadget id="calculator">26 - 90</gadget>
<output>-64</output>

<gadget id="calculator">240 + (-64)</gadget>
<output>176</output>

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

<gadget id="calculator">176 / 1</gadget>
<output>176</output>

<result>176</result>