In a certain pond, 20 fish were caught, tagged, and returned to the pond. A few days later, 20 fish were caught again, of which 2 were found to have been tagged. If the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond, what`s the approximate number of fish in the pond?  Pick.
A) 400
B) 625
C) 1250
D) 2500
E) 500
If x is total number of fish in the pond :   4 = 20/x * 100   =&gt; x = 500   So answer is 500
<result>E</result>
In a certain pond, 20 fish were caught, tagged, and returned to the pond. A few days later, 20 fish were caught again, of which 2 were found to have been tagged. If the percent of tagged fish in the second catch approximates the percent of tagged fish in the pond, what`s the approximate number of fish in the pond?