The mean of marks secured by 65 students in division A of class X is 54, 30 students of division B is 50 and that of 55 students of division C is 48. Find the mean of marks of the students of three divisions of Class X.
Total marks secured by 65 students in division A = 65 $$\times$$ 54 = 3510
Total marks secured by 30 students in division B = 30 $$\times$$ 50 = 1500
Total marks secured by 55 students in division C = 55 $$\times$$ 48 = 2640
=> Mean of marks of the students of three divisions of Class X = $$\frac{(3510 + 1500 + 2640)}{(65 + 30 + 55)}$$
= $$\frac{7650}{150} = 51$$
=> Ans - (C)
Create a FREE account and get: