The total weight of two boxes of goods A and B is (13/15) tons, of which the weight of box A is (7/15) tons, how many tons does the weight of box B weigh?
甲乙两箱货物共重(13/15)吨，其中甲箱货物重(7/15)吨，乙箱货物重多少吨？
<gadget id="calculator">13 / 15</gadget>
<output>13/15 = around 0.866667</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">(13/15) - (7/15)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>