Question: a school has 4 section of chemistry in class x having 70 , 35 , 45 and 42 students . the mean marks obtained in chemistry test are 50 , 60 , 55 and 45 respectively for the 4 sections . determine the overall average of marks per student .
A) 50.9
B) 52.9
C) 51.9
D) 53.25
E) none of the above
Correct answer: c
Grade: 7 | Topic: Statistics and Probability | Difficulty: Medium | Standard: 7.SP.B.3