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. A certain young man was entrusted to the care of a teacher.
P. This dullard will come to grief if I send him away without a single lesson, thought the teacher.
Q. He was so dull of mind that he could not, even in three months time, learn as much as a single lesson.
R. The young man came to ask the teacher's permission to go home.
S. It's my business to provide a good education to my pupils, to get on in life.
S6. The teacher asked him to wait.