Question

The 13 girls in a class got an average mark of 70 in a test. The 7 boys in the same class got an average mark of 60 in the same test. What is the average mark for the whole class?

Answer 1

we know that - (n1.x1+n2.x2)/n1+n2
so. acc. to question 13.60+7.70/13+7= 1270/21=6.4 answer