The average marks of Sam decreased by 1 when he replaced the subject in which he has scored 40 marks by two other subjects in which he has scored 23 and 25 marks respectively. Later, he also included 57 marks of Geography, then the decreased average marks obtained after the first step, increases by 2. How many subjects were present initially?
A. 24
B. 12
C. 15
D. 18
E. 16![]()
A. 24
B. 12
C. 15
D. 18
E. 16