If you put £10000 GBP in to lira account you will have 2,400Ytl
therefore after 1month
24,000Ytl x 12%=2,880Ytl less tax approx @18% =2,361.60 Ytl divide by 12months =198.80 Ytl this is your interest for the month approx £82.
hope this helps, use this forumla for diff exchange rates and % Garanti Bank on deposits upto 25,000USD is 15.5% over this amount is 16.5%