The average mark of the students of a class in a particular exam is 90. If 2 students whose average mark in that exam is 45 are excluded, the average mark of the remaining will be 95. Find the number of students who wrote the exam?  Select
A) 10
B) 40
C) 20
D) 30
E) 25

Rationale: "let the number of students who wrote the exam be x . total marks of students = 90 x . total marks of ( x - 2 ) students = 95 ( x - 2 ) 90 x - ( 2 * 45 ) = 95 ( x - 2 ) 100 = 5 x = > x = 20 answer : c"
Answer: C