Mom made a long-distance call to grandma for 12 minutes, which cost a total of 8.4 yuan. How much is the average fee per minute.
妈妈给外婆打长途电话12分钟，一共花了8.4元．平均每分钟付费多少元．
<gadget id="calculator">8.4 / 12</gadget>
<output>0.7</output>

<result>0.7</result>