Three sentences are given. You need to find if they are grammatically correct or incorrect and mark the answer accordingly.

(P)  It was the first time this important scientific journal had ever published the work of college students.

(Q) In sports, that would be like making the big leagues at the age of fifteen and hitting a home run your first-time at-bat.

(R) For Richard Ebright, it was the first in long string of achievements in science and other fields.