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Math problem please help

A student bake sale is selling baked goods. In total they sell 100 pieces of baking, Chocolate chip cookies sell for $0.50 and Muffins for $1.25. The total money earned from the bake sale came to 68.75. How many muffins did they sell?

1 Answer

9 votes

Answer:

The number of muffins sold by the students is:

  • 25 muffins.

Explanation:

First, we name the variables:

  • C= Number of chocolate chip cookies sold.
  • M= Number of muffins sold.

Now we establish the equations with the information given in the exercise:

  1. C + M = 100
  2. 0.5C + 1.25M = 68.75

We can use in this case the reduction method, to this, we multiply the first equation by (-0.5) obtaining the equation 3:

  • [C + M = 100] * (-0.5) = -0.5C - 0.5M = -50

3. -0.5C - 0.5M = -50

We operate the equations 2 and 3 to eliminate the variable C:

  • (0.5C + 1.25M = 68.75) + (-0.5C - 0.5M = -50) = (0.75M = 18.75)

And we solve for the variable M:

  • 0.75M = 18.75
  • M = 18.75/0.75
  • M = 25

We could stop here because we know the number of muffins now, but with the value for M, we can solve the value of C with the first equation to check the answer is correct:

  • C + M = 100
  • C + 25 = 100
  • C = 100 - 25
  • C = 75

In the end, we replace the values in the second equation and verify if the answer is correct:

  • 0.5C + 1.25M = 68.75
  • 0.5 * (75) + 1.25 * (25) = 68.75
  • 37.5 + 31.25 = 68.75
  • 68.75 = 68.75
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