asked 166k views
1 vote
Mr. Pinter's class has twice as many students as Mrs. Rupert's class. Mrs. Althouse's class has 20 less than three times Mrs. Rupert's class. Together they have 106 students. How many are in each class?

asked
User Duffy
by
8.3k points

1 Answer

3 votes

Answer:

Mr. Pinter's class has 42 students, Mrs. Rupert's class has 21 students, and Mrs. Althouse's class has 43 students.

Explanation:

This question is solved using a system of equations.

I am going to say that:

Mr. Pinter's class has x students.

Mrs. Rupert's class has y students.

Mrs. Althouse's class has z students.

Mr. Pinter's class has twice as many students as Mrs. Rupert's class.

This means that:


x = 2y

Mrs. Althouse's class has 20 less than three times Mrs. Rupert's class.

This means that:


z = 3y - 20

Together they have 106 students.

This means that:


x + y + z = 106

We have x and z has a function of y, so:


2y + y + 3y - 20 = 106


6y = 126


y = (126)/(6)


y = 21

And:


x = 2y = 2(21) = 42


z = 3y - 20 = 3(21) - 20 = 63 - 20 = 43

Mr. Pinter's class has 42 students, Mrs. Rupert's class has 21 students, and Mrs. Althouse's class has 43 students.

answered
User Pavel Shishpor
by
7.9k points
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