An book was sold after a discount of 20% and there was a gain of 20%. If the profit made on it was $6 less than the discount offered on it, find its selling price?  Choose the correct answer.
A) $66  B) $38  C) $77  D) $72  E) $63
$72   $72   Let CP = $100x   SP = $120x   MP = 120x/80 * 100 = $150x   $72 120 /80 * 100= 
<gadget id="calculator">120 /80 * 100</gadget>
<output>150</output>
$150x   $72= $150x - $120x = $30x   $72 - P 150  -  120= 
<gadget id="calculator">150  -  120</gadget>
<output>30</output>
$30x   $72 - P= 30x - 20x = $6, 10x = $6   120x = 120/10 * 6= 
<gadget id="calculator">120/10 * 6</gadget>
<output>72</output>
$72
<result>D</result>
An book was sold after a discount of 20% and there was a gain of 20%. If the profit made on it was $6 less than the discount offered on it, find its selling price?