Answer:
The number of muffins sold by the students is:
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:
- C + M = 100
- 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