Question

mean weight of students in a class is 48kg. if mean weight of girls students is 40kg.and that of boys is 60kg .find (a)% of boys and girls (b) if there are total of 75 students , find number of each ​

Answer 1

Step-by-step explanation:

let no of boys=x and no of girls=y

total students=x+y

as average wt of students=48kg so total wt of all students= 48(x+y) kg

as average wt of boys=60kg so total wt of all boys=60x kg

as average wt of girls=40kg so total wt of all girls=40y kg

total wt of all students=total wt of all boys+total wt of all girls

48(x+y)=60x+40y

48x+48y=60x+40y

60x-48x=48y-40y

12x=8y

x/y=8/12=2/3 ---- ans (a)

(b) x+y=75

from ans (a), x=2y/3

so 2y/3 + y =75

5y/3=75

y=45

x=75-y=75-45=30