Answer:
The cost of each pen is $0.14 and the cost of each pencil is $0.03.
Explanation:
Given:
Paulie ordered 250 pens and 250 pencils.
The pens cost 11 cents more than the pencils.
Her order costs $42.50.
Now, to find the cost of each pen and pencil.
Let the price of a pencil be

So, the price of 250 pencils =

And the price of a pen be

Thus, the price of 250 pens =

Now, to get the cost of each pen and pencil:
According to question:



Subtracting both sides by 27.50 we get:

Dividing both sides by 500 we get:

So, the price of a pencil = $0.03.
And the price of a pen =

Therefore, the cost of each pen is $0.14 and the cost of each pencil is $0.03.