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

Find the number of ways of arranging 15 students A_1,A_2,........A_15 in a row such that (i) A_2 , must be seated after A_1 and A_3 , must come after A_2 (ii) neither A_2 nor A_3 seated brfore A_1

Find the number of ways of arranging 15 students A_1,A_2,........A_15 in a row such that (i) A_2 , must be seated after A_1 and A_3 , must come after A_2 (ii) neither A_2 nor A_3 seated brfore A_1

Find the number of ways of arranging 15 students A_1,A_2,........A_15 in a row such that (i) A_2 , must be seated after A_1 and A_2 , must come after A_2 (ii) neither A_2 nor A_3 seated brfore A_1

Find the number of ways of arranging 15 students A_1,A_2,…….,A_(15) in a row such that A_2 must be seated after A_1 and A_3 must come after A_2

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 candidates A_1,A_2 ,. . . A_(10) can be ranked if A_1 is always above A_2 is

The number of ways in which 10 candidates A_1,A_2,….A_10 can be ranked so that A_1 is always above A_2 is

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 A1