in a school the average age of the boys is 12 and the average age of 32 girls is 15

13.2*(32*15+12*x)=480+12*x
1.2*x=57.6
x=48
total students=48+32=80
10 years agoHelpfull: Yes(3) No(2)
let total no of boys= x and total no of girls= 32
total age of boys= 12x and total age of girls= 32*15= 480;
now total avg age= 13.2 so (12x+480)/(x+32)= 13.2
12x+480= 13.2x+13.2*32
480= 13.2x-12x+422.4
480-422.4=1.2x so 57.6= 1.2x
x= 48 total no of student= x+32 =48+32= 100
ans: total student =100
10 years agoHelpfull: Yes(2) No(3)
let total no of boys= x
total no of girls=32
total age of boys and girls= (12*x)+(32*15)= 12x+480;
now total avg age= 13.2
so (12x+480)=(x+32)*13.2
12x+480= 13.2x + 13.2*32
480= 13.2x-12x+422.4
480-422.4=1.2x
or, 57.6= 1.2x
or, x= 48
therefore, total no of student= x+32 =48+32= 80
ans- total student =80
10 years agoHelpfull: Yes(1) No(0)
assume no. of boys b 'x'
no. of girls is given 32
& average age of girls is 15 so sum of ages of 32 girls is (32*15)=480
sum of ages of boys is (x*12)=12x

total average of class is 13.2 so,
12x+480=13.2(x+32)
solve it for x we get,
57.6=1.2x
so, x=48

then,total no. of students =(32+x) & x=48
ans is 80
10 years agoHelpfull: Yes(0) No(1)
let the no of boys be b.
sum of girls age=32*15=480
now, (480+sum of boys age)/(32+b)=13.2
so,
480+12b=(32+b)*13.2
57.6=1.2b
b=48
total students=32+48=80
10 years agoHelpfull: Yes(0) No(0)
its 80
let the total age of y boys be 'x'and 32 girls be 480
x/y=12=>x=12y
(12y+480)/(32+y)=13.2=>480+12y=422.4+13.2y=>1.2y=57.6=>y=48
so total no.of students=48+32=80
10 years agoHelpfull: Yes(0) No(0)

in a school the average age of the boys is 12 and the average age of 32 girls is 15.

Total average age of the class is 13.2

What is the total no of student in the class.