The mean of marks secured by 55 students in division A of class X is 58, 45 students of division B is 54 and that of 75 students of division C is 52. Find the mean of marks of the students of three divisions of Class X.
Total marks secured by 55 students in division A = 55 $$\times$$ 58 = 3190
Total marks secured by 45 students in division B = 45 $$\times$$ 54 = 2430
Total marks secured by 75 students in division C = 75 $$\times$$ 52 = 3900
=> Mean of marks of the students of three divisions of Class X = $$\frac{(3190 + 2430 + 3900)}{(55 + 45 + 75)}$$
= $$\frac{9520}{175} = 54.4$$
=> Ans - (B)
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