2020 · Q96
The mean weight of 100 students in a class is 46 kg. The mean weight of boys is 50 kg and that of girls is 40 kg. The number of boys exceeds the number of girls by
Elementary MathematicsStatistics
- A10
- B15
- C20
- D25
Explanation
50b+40g = 4600 with b+g = 100 gives b = 60, g = 40; the difference is 20. Hence option (C). Indeed 60 boys and 40 girls give (3000+1600)/100 = 46 kg, matching the data.