A fruit vendor purchased 20 dozens of apples at $15 per dozen. But one-fourth of the apples were rotten and had to be thrown away. He sold two-third of the remaining apples at a$22.50 per dozen. At what price per dozen should he sell the remaining apples to make neither a profit nor a loss?  Choose the correct option.
A) $17 B) $14 C) $15 D) $18 E) $20
C   $15   CP of 20 dozen of apples = 15 * 20= 
<gadget id="calculator">15 * 20</gadget>
<output>300</output>
$300   Number of apples which are rotten= 1/4 * 20= 
<gadget id="calculator">1/4 * 20</gadget>
<output>5</output>
5 dozen.   SP of two-third of remaining apples= (2/3 * 15) * 22.5= 
<gadget id="calculator">(2/3 * 15) * 22.5</gadget>
<output>225</output>
$225   SP of remaining 5 dozens of apples to make no profit and no loss=(300 - 225)= 
<gadget id="calculator">(300 - 225)</gadget>
<output>75</output>
$75.   SP of 1 dozen apples= 75/5= 
<gadget id="calculator">75/5</gadget>
<output>15</output>
$15.
<result>C</result>
A fruit vendor purchased 20 dozens of apples at $15 per dozen. But one-fourth of the apples were rotten and had to be thrown away. He sold two-third of the remaining apples at a$22.50 per dozen. At what price per dozen should he sell the remaining apples to make neither a profit nor a loss?