Let the number of students originally be N. Now we know that there were an equal number of girls and boys.
Therefore number of girls = number of boys = N/2
When 8 girls left the class, the number of girls was N/2 - 8.
Now there were twice as many boys as girls.
Therefore (N/2 - 8)*2 = N/2
=> (N/2)*2 - 16 = N/2
=> N - 16 = N/2
=> N/2 = 16
=> N = 32
Therefore the number of students in the class was 32.
Since the number of girls and boys of the class are equal, we assume that they are x each . Therefore the total students of the class is 2x.
After 8 girls leave for hocky, the left out number of girls = x-8. Now the number boys are 2 times the number of left out girls. So x = 2(x-8).
x = 2x-16.
To solve the above equation we add 16 and subtract x from both sides.
x+16-x = 2x-16+16-x
16 = x.
Therefore x = 16 . So the number of girls = number of boys = 16
Therefore the total students of the class = 2x = 2*16 = 32.
We'll put the number of boys or girls as x.
If 8 girls left to play hockey, the total number of students is:
The number of boys is twice the number of girls:
2(x-8) = x
We'll remove the brackets and we'll get:
2x - 16 = x
We'll subtract x both sides and we'll add 16 both sides:
x = 16
The number of boys is 16 and the number of girls is also 16.
Initially, the total number of students present in classroom is:
16+16 = 32.