Add 15 to the former term of a ratio, and add (1/4) to the latter term, so that the ratio is exactly 1.2 times the original value. What is the former term of this ratio?
一个比的前项加上15，后项增加它的(1/4)，这样比值正好是原来的1.2倍，这个比的前项原来是多少．
<result>30</result>