Li Ming has a deposit of 130 yuan, Wang Fang has a deposit of 70 yuan, Wang Fang wants to catch up with Li Ming, Li Ming saves 10 yuan every month, Wang Fang saves 15 yuan each time, how many months will it take for Wang Fang to catch up with Li Ming ．
李明有存款130元，王芳有存款70元，王芳想赶上李明，李明每月存10元，王芳每次存15元，多少个月后，王芳才能赶上李明．
<gadget id="calculator">130 - 70</gadget>
<output>60</output>

<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<gadget id="calculator">60 / 5</gadget>
<output>12</output>

<result>12</result>