Question

The mean marks of 100 students in a class is 39 the mean mark of the boys is 35 while that of girls is 45 find the number of boys and that of the girls in the class?

Answer 1

Answer:

Let,the total mark of boys= b

Let,the total mark of boys= bthe total mark of girls=g

Let,the total mark of boys= bthe total mark of girls=gtotal no.of boys=x

Let,the total mark of boys= bthe total mark of girls=gtotal no.of boys=xtotal no.of girls=y

so ,the mean mark of boys=b/x=35

the mean mark of girls=a/x=45

the mean mark of girls=a/x=45the mean mark of the total students in the examination=(b+g)/(x+y)=100

the mean mark of girls=a/x=45the mean mark of the total students in the examination=(b+g)/(x+y)=100b=35x. g=45y.

and then,

and then,= (35x+45y)/(x+y)=100

and then,= (35x+45y)/(x+y)=100= 35x+45y = 100x+100y

and then,= (35x+45y)/(x+y)=100= 35x+45y = 100x+100y=-65x=55y

and then,= (35x+45y)/(x+y)=100= 35x+45y = 100x+100y=-65x=55y=-x=(55/65)*y

and then,= (35x+45y)/(x+y)=100= 35x+45y = 100x+100y=-65x=55y=-x=(55/65)*y=x/y=55/65

and then,= (35x+45y)/(x+y)=100= 35x+45y = 100x+100y=-65x=55y=-x=(55/65)*y=x/y=55/65x=55

and then,= (35x+45y)/(x+y)=100= 35x+45y = 100x+100y=-65x=55y=-x=(55/65)*y=x/y=55/65x=55y=65

and then,= (35x+45y)/(x+y)=100= 35x+45y = 100x+100y=-65x=55y=-x=(55/65)*y=x/y=55/65x=55y=65=11/13