Question

30% of all the students in a school are in a play all students except for 140 are in the play how many students are in the school

Answer 1

To figure out how many kids are in the school, you must set up an equation with x representing the number of students. 30% of the students are in the play, so that would be represented by 0.3x. We also know that 140 students are not in the play, that could be represented by x-140. These two equations will equal each other since they both represent the same information, which is the number of children in the play. You set those two equations equal to one another (0.3x = x-140). You then can add 140 to the left side of the equation and subtract 0.3x from the right side. We do this in order to get both values of x on the same side of the equation. We then can simplify the right side of the equation by subtracting 0.3x from 1x. We get 0.7x. Our equation now looks like 140 = 0.7x. We must now divide each side of the equation by 0.7 in order to get the x all by itself and find its value. 140 divided by 0.7 is 200. The number of students in the school is 200.