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the mean mark for the class was 70%. There are 30 students in the class, 20 of whom are boys. The mean mark for the boys is 62%. What is the mean mark for the girls?

Respuesta :

Mean mark for the class = 70%
Total marks for the class = 70 x 30 = 2100

Mean mark for the boys = 62%
Total marks for the boys = 62 x 20 = 1240

Total marks for the girls = 2100 - 1240 = 860
Mean marks for the girls = 860 ÷ 10 = 86%

Answer: 86%