Let x = Total fish in the pond
So the number of tagged fish in the pond = 50

2/50 = 1/25

So the 50 tagged fish represent 1/25 of the total fish

50* 25 = 1250 total fish

C is the logical answer from my perspective too but the answer book states that the correct answer is (b) or 625.

Just making sure I wasnt overlooking something.

Thanks,

cgc wrote:In a certain pond, 50 fish were caught, tagged, and returned to the pond. A few days later, 50 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 is the approximate number of fish in the pond?

(a) 400
(b) 625
(c) 1,250
(e) 2,500
(f) 10,000

any suggestions?

Since the percent of tagged fish in the second catch, which is 2/50 times 100 or 4%, approximates the percent of tagged fish in the pond, which are with intent, 50 in number; so we can fix on the number whose 4% is 50, as 1,250...but!! Why did they make the second catch? I guess, it was done for the same tagging process, and they had to tag only 48, tagged totaled in the pond to 98 now. So we should better ask for the approximate number whose 4% is 98, which is undoubtedly [spoiler]625[/spoiler] in the choices. [spoiler]B[/spoiler]