Answer
Find out the how much prize money did she win.
To proof
Let us assume that the total amount prize money did she win be u.
As given
Mrs.Gill won certain prize money in a cooking competition.
She spent half of the prize money on the clothes
one third on grocery
(L.C.M of (2,3) =6 )
gave away the remaining Rs.2000 to an orphanage
u =Rs 12000
Rs 12000 prize money did she win.
Hence proved