If you have 4 New Year greeting cards and you want to send them to 2 of your friends, in how many ways can this be done? Choose the correct answer.
A) 360 B) 12 C) 16 D) 24 E) None
Solution   We have to find number of permutations of 2 objects out of 4 objects. This number is 4P2=4(4-1)=4*3= 
<gadget id="calculator">4*3</gadget>
<output>12</output>
12   Answer 12
<result>B</result>
If you have 4 New Year greeting cards and you want to send them to 2 of your friends, in how many ways can this be done?