The last time Parag bought Diwali cards, he found that the four types of cards that he liked were priced Rs.2.50, Rs.3.50, Rs.3.00 and Rs.5.00 each. As Rahul wanted 50 cards, he took ten each of two kinds and fifteen each of the other two, putting down the exact number of 10 rupees notes on the counter payment. How many notes did paragl give?	Choose the correct choice from the following:
A) 10	B) 12	C) 15	D) 11	E) 18
Explanation :   Let the four cards be a, b ,c and d. 'x' be the number of notes.   Then, according to the question,   =&gt;10a + 10b + 15c + 15d = 10*x.   =&gt; a +b + 1.5(c+d) = x . -----------------------------(i)   Since, a + b = 2.50+3.50= 
<gadget id="calculator">2.50+3.50</gadget>
<output>6</output>
6.   And,=&gt; c + d = 3+5= 
<gadget id="calculator">3+5</gadget>
<output>8</output>
8   Putting these values in (i), we get :-=&gt; 6 + 1.5 * 8 = x.   =&gt; x = 18 .   Answer : 18
<result>E</result>
The last time Parag bought Diwali cards, he found that the four types of cards that he liked were priced Rs.2.50, Rs.3.50, Rs.3.00 and Rs.5.00 each. As Rahul wanted 50 cards, he took ten each of two kinds and fifteen each of the other two, putting down the exact number of 10 rupees notes on the counter payment. How many notes did paragl give?