Answer:
$0.25 per donut.
Step-by-step explanation:
So, we know that Jamie spends the same amount of money each morning.
On Sunday, he spent $1.25 on a newspaper and bought 2 donuts.
On Monday, he spent $0.50 on a newspaper and bought 5 donuts.
Since he spend the same amount of money each morning, we can say that:

Where x represents the cost per donut.
So, to find the cost of a donut, we need to solve for x.
So, let's try to isolate the x. Subtract 2x from both sides:

The left side cancels. Subtract on the right:

Now, let's subtract 0.5 from both sides:

To find x, divide both sides by 3:

Divide:

Therefore, each donut cost $0.25.
And we're done!