There are five numbers, the average of which is 140, the average of the first three numbers is 125, and the average of the last three numbers is 160, what is the third number?
有五个数，其平均数为140，前三个数的平均数是125，后三个数的平均数为160，第三个数是多少．
<gadget id="calculator">125 * 3</gadget>
<output>375</output>

<gadget id="calculator">160 * 3</gadget>
<output>480</output>

<gadget id="calculator">140 * 5</gadget>
<output>700</output>

<gadget id="calculator">480 - 700</gadget>
<output>-220</output>

<gadget id="calculator">375 + (-220)</gadget>
<output>155</output>

<result>155</result>