There are two empty cubic water tanks A and B with the same volume, and there are drainage holes A and B on their sides respectively. The distances between hole A and hole B and the bottom surface are (5/6) and (1/2) the height of the water tank respectively, and the speed is the same when draining. Now inject water into the two water tanks together at the same speed, and let the water discharged from hole A flow into the second tank directly through the pipe, so that after 70 minutes, the water tanks A and B are filled at the same time. Let me ask: If you fill tank B with water at the above speed, how many minutes will it take for tank B to go from empty to full?
有甲、乙两个容积相同的空立方体水箱，在它们的侧面上分别有排水孔A和B．A孔和B孔与底面的距离分别是水箱高度的(5/6)和(1/2)，且在排水时速度相同．现在以相同的速度一起向两水箱注水，并通过管道使A孔排出的水直接流入乙箱，这样经过70分钟后，甲、乙两水箱恰好同时被注满．试问：如果以上述的速度向乙箱注水，乙箱从空到满需要多少分钟？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 - (5/6)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(5/6) - (1/2)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/6) / (1/3)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">70 / 7</gadget>
<output>10</output>

<gadget id="calculator">(1/2) * 10 * 6</gadget>
<output>30</output>

<gadget id="calculator">(1/2) * 10 * 6 * 2</gadget>
<output>60</output>

<gadget id="calculator">30 + 60</gadget>
<output>90</output>

<result>90</result>