The quality of grains stored in warehouses A and B are equal. After 8 tons of grains are taken out from warehouse A and put into warehouse B, the mass ratio of grains stored in warehouses A and B is 4:5. How many tons of grain did Warehouse A originally have? (Please use ratio to solve)
甲、乙两个仓库所存粮食的质量相等，从甲仓库中取出8吨粮食放入乙仓库后，甲、乙两个仓库所存粮食的质量比是4：5．甲仓库原来有多少吨粮食？(请用比例解)
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(4/5) * 8</gadget>
<output>32/5 = around 6.4</output>

<gadget id="calculator">8 + (32/5)</gadget>
<output>72/5 = around 14.4</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(72/5) / (1/5)</gadget>
<output>72</output>

<result>72</result>