The average marks in mathematics scored by the students of a school at the public examination were 39. If four of these students who actually scored 5, 12, 15 and 19 marks at the examination had not been sent up, the average marks for the school would have been 44. Find the number of students sent up for examination from the school?
A. 20
B. 25
C. 30
D. 32
39x = 5 + 12 + 15 + 19 + (x – 4)44
x = 25