The ratio of a to b is 5:7, a is 30, what is b?
a与b的比是5：7，a是30，b是多少？
<gadget id="calculator">7 / 5</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">30 * (7/5)</gadget>
<output>42</output>

<result>42</result>