The latter term of a ratio is (7/10), and the ratio is 15. What is the former term of this ratio?
一个比的后项是(7/10)，比值是15，这个比的前项是多少．
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">15 * (7/10)</gadget>
<output>21/2 = around 10.5</output>

<result>21/2 = around 10.5</result>