Uncle Wang, a "fish farming expert", wanted to count the number of fish in his fish pond. Last month, he randomly caught 50 fish from the fish pond, marked the 50 fish and put them back into the fish pond In this month, another 200 fish were randomly caught from the fish pond, and 2 of them were found to be marked. How many fish are raised in this fish pond? (assuming that the number of fish has not changed during the measurement period)
"养鱼能手"王伯伯想测算出自己鱼塘中鱼的条数，他上个月从鱼塘中随机地捕捉了50条鱼，并对这50条鱼作了记号后又放回鱼塘中，这个月又从鱼塘中随机地捕捉了200条鱼，发现其中2条鱼是有标记的，这个鱼塘大约养鱼多少条？(假设在测算期间鱼的条数没有变化)
<gadget id="calculator">2 / 200</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(1/100) * 1</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">50 / (1/100)</gadget>
<output>5_000</output>

<result>5_000</result>