a cup of coffee cost .75 cents more than a donut, angelo buys 6 donuts and 2 muffins which cost 12.50 total. how much does 1 muffin cost

Let's say the cost of a donut is x.

Therefore, the cost of a cup of coffee is x + $0.75.
The cost of 6 donuts is 6x.
The cost of 2 muffins is 2 * cost per muffin = $2x.
The total cost of 6 donuts and 2 muffins is 12.50, so 6x + 2x = 12.50.
Combining like terms, we get 8x = 12.50.
Dividing both sides by 8, we get x = 12.50 / 8 = $1.5625.
Therefore, the cost of one muffin is $2x = $2 * $1.5625 = $3.125. Answer: \boxed{3.125}.

To find the cost of one muffin, we can set up a system of equations based on the given information. Let's define the variables:

Let x be the cost of one donut.
Given that a cup of coffee costs $0.75 more than a donut, we can define the cost of a cup of coffee as x + $0.75.

Now, let's create an equation based on the total cost of Angelo's purchase:
6 donuts * x + 2 muffins * (cost of one muffin) + 2 muffins * (cost of one coffee) = $12.50

Since Angelo buys 2 muffins, the total cost of muffins is 2 * (cost of one muffin), and the total cost of coffee is 2 * (cost of one coffee).

Substituting the previously defined values into the equation, we get:
6x + 2(cost of one muffin) + 2(x + $0.75) = $12.50

Now, we can simplify the equation:
6x + 2(cost of one muffin) + 2x + 1.50 = $12.50

Combining like terms:
8x + 2(cost of one muffin) + 1.50 = $12.50

Now, let's isolate the variable:
8x + 2(cost of one muffin) = $12.50 - $1.50
8x + 2(cost of one muffin) = $11.00

Subtracting 2(cost of one muffin) from both sides of the equation:
8x = $11.00 - 2(cost of one muffin)

Since we want to find the cost of one muffin, we'll express it on one side of the equation:
2(cost of one muffin) = $11.00 - 8x

Now, divide both sides of the equation by 2 to solve for the cost of one muffin:
(cost of one muffin) = ($11.00 - 8x) / 2

So, the cost of one muffin is ($11.00 - 8x) / 2.

Let's set up a system of equations to solve this problem:

Let D be the cost of one donut.
Then the cost of one cup of coffee would be D + 0.75 cents.

According to the given information:
6 donuts would cost 6D.
2 muffins would cost 2M.
And the total cost of 6 donuts and 2 muffins is $12.50.

So, we have the equation: 6D + 2M = 12.50.

Now let's solve for the cost of one muffin, M:

From the first equation, we know that the cost of one cup of coffee is D + $0.75.
Since Angelo did not buy any coffee, the cost of the coffee is zero.

So, the equation becomes: 6D + 2M + 0 = 12.50.
Simplifying the equation: 6D + 2M = 12.50.

Now we have a system of two equations:
6D + 2M = 12.50, and
D + 0.75 = 0.

From the second equation, we can determine the value of D:
D = -0.75.

Substituting this value into the first equation:
6(-0.75) + 2M = 12.50.
Simplifying the equation: -4.50 + 2M = 12.50.

Next, isolate the variable M by subtracting -4.50 from both sides:
2M = 12.50 + 4.50.
Simplifying the equation: 2M = 17.

Finally, divide both sides by 2 to solve for M:
M = 17 / 2.

Therefore, one muffin costs $8.50.