In a class of 100 students, mean marks obtained in a subject is 30 and in another class of 50 studen

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In a class of $100$ students, the mean marks obtained in a subject is $30$ and in another class of $50$ students the mean marks obtained in the same subject is $60 .$ The mean marks obtained by the students of two classes taken together is

A

$40$

B

$45$

C

$48$

D

$50$

Solution

total marks obtained by $150$ students.

$=100 \times 30+50 \times 60=6000$

mean marks $=\frac{6000}{150}=40$

Standard 13

Quantitative Aptitude

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