To transport 840 tons of goods, assign tasks according to the number of vehicles in the transport team. It is known that the ratio of the number of vehicles in the three transport teams A, B, and C is 6:8:7, so how many tons should team B transport more than team A?
要运输840吨货物，按运输队的汽车辆数分配任务．已知甲、乙、丙三个运输队的汽车辆数比是6：8：7，那么乙队应比甲队多运货多少吨？
<gadget id="calculator">6 + 8 + 7</gadget>
<output>21</output>

<gadget id="calculator">8 / 21</gadget>
<output>8/21 = around 0.380952</output>

<gadget id="calculator">840 * (8/21)</gadget>
<output>320</output>

<gadget id="calculator">6 / 21</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">840 * (2/7)</gadget>
<output>240</output>

<gadget id="calculator">320 - 240</gadget>
<output>80</output>

<result>80</result>