Lesson One unusual problem to solve using system of two equations

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One unusual problem to solve using system of two equations


Problem 1

Three kinds of tickets are sold for a school student parent dinner:  a  $1.00 ticket for one adult,
 a  $1.50 ticket for one adult and one child and  $2 ticket for  2 adults and one child.
Total raised was  $69  and  32 children and  62 adults attended.  How many of each type of ticket was sold?

Solution

Let x be the number of $1.50 tickets for 1 adults and one child.

Let y be the number of $2    tickets for 2 adults and one child.

Then the number of $1 tickets for single adult is (62-x-2y).


Then you have these two equations:

   x +  y             = 32     (1)    (counting children)
1.5x + 2y + (62-x-2y) = 69     (2)    (counting money)


Simplify: 

   x +  y = 32,                (3)
0.5x      = 69-62 = 7          (4)


Simplify again:

   x +  y = 32,                (5)
0.5x      =  7.                (6)


It is clear now from (2) that  x = 2*7 = 14.

Then from (1)  y = 32 - x = 32 - 14 = 18.



Answer.  14 $1.50 tickets;  18 $2 tickets;  and the number of $1 tickets is 62-x-2y = 62-14-2*18 = 12.


The lesson to learn from this solution:

     In standard word problems solved using systems of two equations, creating a system of equations is not a difficult task.

     But in this case you need to stench your mind to do it correctly . . . 

     This is why I placed this lesson and this problem here.


     I wanted, most of all, to reduce the problem to 2 equations and avoid having 3 equations.

     And I succeeded in it.  Now I want to familiarize you with this approach/technique.


My other lessons in this site on solving systems of two linear equations in two unknowns  (Algebra-I curriculum)  are
    - Solution of the linear system of two equations in two unknowns by the Substitution method
    - Solution of the linear system of two equations in two unknowns by the Elimination method
    - Solution of the linear system of two equations in two unknowns using determinant
    - Geometric interpretation of the linear system of two equations in two unknowns
    - Useful tricks when solving systems of 2 equations in 2 unknowns by the Substitution method
    - Solving word problems using linear systems of two equations in two unknowns

    - Word problems that lead to a simple system of two equations in two unknowns
    - Oranges and grapefruits
    - Using systems of equations to solve problems on tickets
    - Three methods for solving standard (typical) problems on tickets
    - Using systems of equations to solve problems on shares
    - Using systems of equations to solve problems on investment
    - Two mechanics work on a car
    - The Robinson family and the Sanders family each used their sprinklers last summer
    - Roses and vilolets
    - Counting calories and grams of fat in combined food
    - A theater group made appearances in two cities
    - Exchange problems solved using systems of linear equations
    - Typical word problems on systems of 2 equations in 2 unknowns
    - HOW TO algebraize and solve these problems on 2 equations in 2 unknowns
    - Non-standard problem with a tricky setup
    - Sometimes one equation is enough to find two unknowns in a unique way
    - Solving mentally word problems on two equations in two unknowns
    - Solving systems of non-linear equations by reducing to linear ones
    - Solving word problems for 3 unknowns by reducing to equations in 2 unknowns
    - System of equations helps to solve a problem for the Thanksgiving day
    - Using system of two equations to solve the problem for the day of April, 1

    - OVERVIEW of lessons on solving systems of two linear equations in two unknowns

Use this file/link  ALGEBRA-I - YOUR ONLINE TEXTBOOK  to navigate over all topics and lessons of the online textbook  ALGEBRA-I.


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