Question
In a class of 50 students, the girls are 76%. The
average weight of boys is 62 kg and that of girls is 58 kg. What is the average weight (in kg) of whole class?Solution
Total students = 50 Numbers of girsl = 50 × (76/100) = 38 Number of boys = 50 – 38 = 12 For easy calculation, Ratio of girls to boys = 38 : 12 = 19 : 6 Let number of boys 6 and number of girls 19, then Average weight of 6 boys = 62 kg Sum of weight of 6 boys = 62 × 6 = 372 Average weight of 19 girls = 58 kg Sum of weight of 19 girls = 58 × 19 = 1102 Total weight of 19 girls and 6 boys = 372 + 1102 = 1474 Average weight of 25 students = 1474/25 = 58.96
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