The following six sentences come from a paragraph. The first and the last sentences are given. Choose the order in which the four sentences (PQRS) should appear to complete the paragraph.
S1 : Gopal worked as a labourer at the building site.
S6 : He unscrewed the lid and found a valuable collection of old silver in it.
P : But Gopal made a bid and he got the box.
Q : There was no key to it and it seemed useless, but Gopal took it home.
R : Once while returning from his work Gopal stopped at an auction sale.
S : No one seemed to want a rough old box when it was put up for sale.
Select the correct sequence.