In a class of 60 students, 40% are girls. The average of the girls marks is 45 and that of the boys is 75. What are the average marks of the whole class?
Answer & explanation
Correct answer: option 4
Ratio ⇒ Boys : Girls
3 : 2
Avg marks of class = \(\frac{3 × 75 + 2 × 45}{3 + 2}\)
= \(\frac{225 + 90}{5}\) = \(\frac{315}{5}\) = 63