In a class of 45 students, there are 20 girls who scored an average of 42 marks in a test of 50 marks. If the class average is 36, what are the average marks of the boys?
Answer & explanation
Correct answer: option 4
Number of boys = 45 - 20 = 25
Let average marks of boys = B
ATQ,
20×42 + 25×B = 45× 36
840 + 25B = 1620
25B = 780
B = 31.2
So , average of boys = 31.20