Soft Drink Bottle Puzzle
A shopkeeper gives a full bottle of soft drink in return for five empty bottles.
A guy has 77 empty bottles and he can use them to get full soft drink bottles.
How many filled bottles will he be able to get from the shopkeeper?
The Guy can get 19 filled bottles from the shopkeeper.
First he returns 75 empty bottles and gets 15 full soft drink bottles.(2 emptly bottles left)
Now from 15 bottles he gets 3 full soft drink bottles.
Now using these 3 and earlier 2 bottles, He gets 1 full soft drink bottle.
So in total he can get 15+3+1=19 full soft drink bottles.