frog jumps from the bottom of the well to the mouth of the well. If it jumps 3 meters a day, it will be 2 days later than the original time. If it jumps 5 meters a day, it will be 2 days earlier than the original time. How many meters is the wellhead to the bottom of the well?
一只青蛙从井底往井口跳，若每天跳3米，则比原定时间迟2天，若每天跳5米，则比原定时间早2天．井口到井底有多少米？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">6 + 10</gadget>
<output>16</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">8 + 2</gadget>
<output>10</output>

<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<result>30</result>