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MCQ
A class of 30 students has mean marks 60 and a class of 20 students has mean marks 50. The mean marks of all 50 students are:
Unit-11 Basic Statistics
A 54
B 55
C 56
D 58
Explanation

Combined mean = (30 x 60 + 20 x 50)/50 = (1800 + 1000)/50 = 2800/50 = 56.

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