Two buckets of water, A and B, weigh a total of 100 kg. If 15 kg of water is poured from bucket A to bucket B, then the weight of the water in bucket A is three times the weight of the water in bucket B. It turns out how many kilograms of water is in bucket B.
甲、乙两桶水共重100千克．如果从甲桶倒出15千克水给乙桶，那么甲桶里水的重量是乙桶里水的重量的3倍．原来乙桶有水多少千克．
<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">25 * 1</gadget>
<output>25</output>

<gadget id="calculator">25 - 15</gadget>
<output>10</output>

<result>10</result>