Find the number of subsets of the set {1,2,3,4,5,6,7,8,9,10,11} having 4 elements.?	Select the correct option.
A) 1320
B) 660
C) 165
D) 330
E) None of these
Explanation :   Here the order of choosing the elements doesn’t matter and this is a problem in combinations.We have to find the number of ways of choosing 4 elements of this set which has 11 elements.This can be done in:11C4=11*10*9*81*2*3*4= 330 ways   Answer : 330
<result>D</result>
Find the number of subsets of the set {1,2,3,4,5,6,7,8,9,10,11} having 4 elements.?