According to 3a=4b, it is written as a ratio. If the product of the two external terms of this ratio is equal to 8, then b=how much.
根据3a=4b写成一个比例，如果这个比例两个外项的积等于8，则b=多少．
<gadget id="calculator">8 / 4</gadget>
<output>2</output>

<result>2</result>