Q29
The mean weight of 100 students in a class is 46 kg. The mean weight of boys is 50 and of girls is 40 kg. Therefore, the number of boys is:
A.
50
B.
60
AnswerC.
70
D.
65
Answer: Option B
Solution
Answer: Option B
Solution:
Let number of boys are x and then number of girls= (100 - x)
Thus,
50x + (100 - x) × 40 = 46 × 100
→ x = 60
Number of boys = 60