55% of the studnts in a school are girls.find the total no. of studnt in the school if the no. of boys is 18 .

S = Numbers of students

Percent of boys.

100 % - 55 % = 45 % = 45 / 100

45 % S = 18

45 S / 100 = 18 Multiply both sides by 100

45 S = 18 * 100

45 S = 1800 Divide both sides by 45

S = 1800 / 45 = 40