I have 50rs I spend 20rs- remain 30rs I spend 15rs- remain15rs I spend 09rs- remain 06rs I spend?

i have 50 i spend 20 remain 30 i spend 15 you have 15 left so now you spend 9 you have 06 remaining so if you spend 5 you have a total of 1 remaining then you have the 50 you started with with 1 remaining thats 51 alltogether hope i did that right