Question

The average mean of 70 boys and 30 girls in mathmatics is 72 . if the average marks of 70 boys is is 75 . what is the average marks of 30 girls​

Answer 1

Answer:

Given :---

Average of 70B+30G is 72 .

so, sum of 100 students of class = 72*100 = 7200

as average = Total age/number of students

now, it has been said that,

average of 70 boys is 75.

so, sum of ages of boys = 70*75 = 5250

so,

sum of ages of 30 girls = 7200-5250 = 1950

their average age = 1950/30 = 65 (Ans)

(Mark as brainlist)