The number of ways in which 10 candidates `A_1,A_2, A_(10)` can be ranked such that `A_1` is always above `A_(10)` is a. `5!` b. `2(5!)` c. `10 !` d. `1/2(10 !)`

The number of ways in which ten candidates A_1, A_2, ...., A_(10) can be ranked so that A_1 is always above A_2 is

The number of ways in which ten candidates A_(1),A_(2),............A_(10) be ranked such that A_(1) is always above A_(10)

The number of ways in which 10 condidates A_(1),A_(2),......,A_(10) can be ranked so that A_(1) is always above A_(2) , is

Find the number of ways in which the candidates A_(1),A_(2),A_(3).........,A_(10) can be ranked.

Find the number of ways of seating 10 students A_(1),A_(2).....A_(10) in a way that A_(1),A_(2),A_(3) sit together

In how many ways 10 persons A_(1),A_(2),A_(3),A_(4),...,.,A_(10) can be seated along a row such that A_(2),A_(3),A_(4) sit always after A_(1) is..

In how many 10 persons A_(1),A_(2),A_(3),....A_(10) can be arranged along row in such a way that A_(2) must always occupy the middle place to that of A_(1),A_(3). (i) 20*8! (ii) 20*7! (iii) 40*7!( iv )2!

The capacitance of the capacitors of plate areas A_1 and A_2(A_1 lt A_2) at a distance d is

If the points (a,b),(a_1,b_10 and (a-a_1,b-b_1) are collinear, show that a/a_1=b/b_1

If 1, a_1,a_2,a_3 ,…, a_(n-1) are the nth roots of unity then prove that : 1+a_1+a_2+…+a_(n-1) =0.