A boy buys 18 sharpners, (Brown/white) for Rs.100. For every white sharpener, he pays one rupee more than the brown sharpener. What is the cost of white sharpener and how much did he buy?	Choose the correct answer.
A) 3.9 B) 3,6 C) 2,3 D) 22,2 E) 12,1
C   Assume that he bought b, brown sharpeners and w, white sharpeners and the cost of brown sharpener is x and white sharpener is x + 1   So w(x+1) + bx = 100   w + b = 18   b = 18 - w   Substituting in equation 1, we get w(x+1) + (18 -w)x = 100 so w + 18 x = 100   Take option 1: If white sharpners are 13, x = (100 - 13) /18 = 4.833   Option 2, If white sharpeners are 10, x = (100 - 10)/18= 
<gadget id="calculator">(100 - 10)/18</gadget>
<output>5</output>
5 So white sharpeners cost is 6.   Option 3 Satisfies this condition.   Answer:3,6
<result>B</result>
A boy buys 18 sharpners, (Brown/white) for Rs.100. For every white sharpener, he pays one rupee more than the brown sharpener. What is the cost of white sharpener and how much did he buy?