The task is to generate the correct answer for a given math problem.

[EX Q]: Problem: a house wife saved $ 5 in buying an item on sale . if she spent $ 48 for the item , approximately how much percent she saved in the transaction ?
[EX A]: 10 %

[EX Q]: Problem: a rectangle having length 105 cm and width 40 cm . if the length of the rectangle is increased by twenty five percent then how much percent the breadth should be decreased so as to maintain the same area .
[EX A]: 19.23 %

[EX Q]: Problem: 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 5 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 ?
[EX A]:
500