A boy has 5 pens out of which a pair is to be selected for an examination. At most, how many different pairs are possible?  Choose the correct answer:
A) 20
B) 10
C) 5
D) 40
E) 10
N=5C2=5!/(3!2!)=5*2= 
<gadget id="calculator">5*2</gadget>
<output>10</output>
10   Correct Option: 10
<result>E</result>
A boy has 5 pens out of which a pair is to be selected for an examination. At most, how many different pairs are possible?