1x1 = 1 !!
Hope this helped.
Percentage of students that are girls in the class = 60%
Number of girls in the class = 18
Let us assume the total number of students in the class = x
Then
60% * x = 18
(60/100) * x = 18
6x/10 = 18
6x = 18 * 10
6x = 180
x = 180/6
= 30
So the total number of students in the class is 30.
Number of boys in the class = 30 - 18
= 12
So there are 12 boys in the class. I hope the procedure is simple enough for you to understand.
The answer is mostly likely B
103+53=156
156/2=78
The average or mean is 78
The answer would be 1380000