The number of all three element subsets of the set `{a_(1),a_(2),a_(3)......a_(n)}` which contain `a_(3)` , is

The number of all three element subsets of set {a_(1),a_(2),a_(3),.......,a_(n)} which contain a_(3) is

Find the number of all three elements subsets of the set {a_(1),a_(2),a_(3),.............a_(n)} which contain a_(3) .

The number of all the four element subsets of the set {a_(1),a_(2),a_(3),......,a_(n)} aan which contain a_(3) but do not contain a_(n-3),(n>=6) is

If one quarter of all three element subsete of the set A={a_(1),a_(2),a_(3),......,a_(n)} contains the element a_(3) , then n=

If one quarter of all three element subsete of the set A={a_(1),a_(2),a_(3),......,a_(n)} contains the element a_(3) , then n=

If one quarter of all three element subsets of the set A={a_(1), a_(2), a_(3), ......., a_(n)} is equal to the three element subsets which contains the element az, then n is

If 20% of three subsets (i.e.subsets containing exactly three elements of the set A={a_(1),a_(2),......a_(n)} contain a_(1), then value of 'n'

The number of subsets of the set A={a_(1),a_(2), . . .,a_(n)} which contain even number of elements is

The number of subsets of the set A={a_(1),a_(2), . . .,a_(n)} which contain even number of elements is

The number of subsets of the set A={a_(1),a_(2),………..a_(n)} which contain even number of elements is