Question

the mean wieght of students in a certain class is 60kg . the mean weight of bous is 70 and girls is 55 . find ratio
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Answer 1

Answer:

ratio of what is to be found. not that of weight I guess. it should be ratio of numbers of boys to girls.

let no. of boys be x and that of girls be y

total weight of boys = mean weight x no. of boys

= 70x

total weight of girls = 55y

total weight of students = 60(x + y))

thus

70x + 55y = 60(x +y)

70x + 55y = 60x + 60y

70x - 60x = 60y - 55y

10x = 5y

x/y = 5/10

x/y = 1/2