Question : If the papers of 4 students can be checked by any one of the 7 teachers, then the probability that all the 4 papers are checked by exactly 2 teachers is

(A) 2/7

(B) 12/49

(C) 32/343

(D) none of these

Answer : option

Solution :

with
no comment

Question : If the papers of 4 students can be checked by any one of the 7 teachers, then the probability that all the 4 papers are checked by exactly 2 teachers is

(A) 2/7

(B) 12/49

(C) 32/343

(D) none of these

Answer : option

Solution :