#### Answer

$\$87$

#### Work Step by Step

Pens were purchased at $\$0.95$ per dozen.
They were sold at $\$2.25$ for four.
To get the profit on $15$ dozen pens, we can simply:
1. Take the selling price of one pen, and multiply it by 12, to get the selling price of a dozen pens.
$(2.25\div4)*12=2.25*3=6.75$ (dollars for a dozen pens)
The profit per dozen pens is then:
$6.75 – 0.95 = 5.80$ (dollars)
Which makes the profit for 15 dozen pens:
$5.80*15=87$ (dollars)