There is 15.6 liters of water in bucket A, and after pouring 1.8 liters into bucket B, it is 0.2 liters less than bucket B. How many liters of water is in barrel B? (solution by equation)
甲桶有水15.6升，倒给乙桶1.8升后比乙桶少0.2升．乙桶原有水多少升？(用方程解)
<gadget id="calculator">15.6 - 1.8</gadget>
<output>13.8</output>

<gadget id="calculator">1.8 - 0.2</gadget>
<output>1.6</output>

<gadget id="calculator">13.8 - 1.6</gadget>
<output>12.2</output>

<result>12.2</result>