If Ryan has 20% more notebook than justin.and Ryan have 18 notebook then Justin have how many notebooks? Answers:  A) 16  B) 14  C) 12  D) 15  E) 10
lets Justin have x notebook.   (18-x)*100/x=20   1800-100x=20x   120x=1800   x=1800/120= 
<gadget id="calculator">1800/120</gadget>
<output>15</output>
15   answer 15
<result>D</result>
If Ryan has 20% more notebook than justin.and Ryan have 18 notebook then Justin have how many notebooks?