Question

A lady went shopping.
She spent half the total money she had on groceries.
She spent 1/3 the total money she had on transport.
She lost 1/4 the total in a gutter.
When she got home she had $15.

Q: How much did she have when she left home?

Answer 1

Here when you say  total money, it means the amount of money she has at that moment.

 let the amount she started with  be  S.

   S/2  on groceries.    left with :  S/2
   1/3 rd of it  on  transport:  so S/6.      She is left with  S/2 - S/6 = S/3
   she spent  1/4th of that remaining in  a gutter.
             So that is:  S/12.        She is left with  S/3 - S/12 = S/4

   So then  S/4 = $15

         She started with  a sum of $60.