In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?
Looking at the portrait of a girl, Sheesha, a girl, said, "Her mother is my grandfather's only daughter who has only one daughter and no sons". How is Sheesha related to the girl in the portrait?
Vijay can do a work in 8 hours. Vijay and Puneet together can do the same work in 6 hours. Puneet and Sachin together can do the same work in 4 hours. Sachin alone can complete the same work in how many hours?