Thirty percent of all the students in a school are in a play. All students except for 140 are In the play.

Tutors, sign in to answer this question.

Kevin F. | Computer Programming and Mathematics TutorComputer Programming and Mathematics Tut...

Let x = the total number of students, and p = number of students in the play.

If 30 percent of students are in the play:

.3x = p

If All except for 140 are in the play:

x - 140 = p

Now we have 2 equations, so use substitution to solve for x:

x - 140 = .3x

x - .3x = 140

.7x = 140

x = 140 / .7 = 200

Now that we know x, solve for p:

200 - 140 = p

60 = p

There are 200 students total, and 60 in the play.

30% are in the play

70% are not in the play

140 are not in the play

140 is 70% of total # of students(call this n)

140=70%*n

140=0.7n

1400=7n

1400/7=n

200=n

Derek W. | Math and Science Tutor in Cabot AreaMath and Science Tutor in Cabot Area

What you know: 30% of all students in play & 140 students not in the play

What you need to know: # of students in school

Formulas: Total Students in School x % in play = # students in play

Students in play + Students not in play = Total Students in School

If you merge the two formulas you get: Total Students in School = (Total Students x % in play) + students not in play.

Plug in the numbers: Total Students = (Total Students x 30%) + 140 -or- x=.30x+140

Solve for x:

Subtract 0.30x from both sides: x-.3x = 140 -or- .7x = 140

Divide both sides by .7: 0.7x / 0.7 = 140 / 0.7

You get x = 200. So there are 200 students in the school

Hi Travina;

30%=0.30

x=total number of students

(0.30)x=x-140

Let's subtract x from both sides...

-x+(0.30)x=-140

-(0.70x)=-140

Let's divide both sides by -0.70

-(0.70x)/(-0.70)=-140/(-0.70)

x=200

30% of 200=0.30(200)=60 students in play

140 are exceptions who are not in play.

60+140=200

Already have an account? Log in

By signing up, I agree to Wyzant’s terms of use and privacy policy.

Or

To present the tutors that are the best fit for you, we’ll need your ZIP code.

Your Facebook email address is associated with a Wyzant tutor account. Please use a different email address to create a new student account.

Good news! It looks like you already have an account registered with the email address **you provided**.

It looks like this is your first time here. Welcome!

To present the tutors that are the best fit for you, we’ll need your ZIP code.

Please try again, our system had a problem processing your request.