Question 1188845
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The system of equations is


      x +  y =  18    (1)    (counting problems)

     5x + 8y = 111    (2)    (counting points)


You can solve it by many methods (Substitution, Elimination, determinants).


Substitution method gives  x = 18-y, and then from equation (2)


    5(18-y) + 8y = 111

    90 - 5y + 8y = 111

           3y    = 111 - 90 = 21

            y               = 21/3 = 7.


<U>ANSWER</U>.  7 short-answer problems and 18-7 = 11 multiple choice problems.


<U>CHECK</U>.  7*8 + 11*5 = 56 + 55 = 111 points, in total.   ! Correct !
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Solved.