If 5% more is gained by selling an book for $ 350 than by selling it for $ 340, the cost of the book is:
Choose the most appropriate option:	A) 500	B) 400	C) 200	D) 300	E) 100
C   200   Let C.P. be $ x.   Then, 5% of x = 350 - 340= 
<gadget id="calculator">350 - 340</gadget>
<output>10</output>
10   x/20= 10 =&gt; x = 200
<result>C</result>
If 5% more is gained by selling an book for $ 350 than by selling it for $ 340, the cost of the book is: