The number of ways of arranging seven persons (having A,B,C and D among them) in a row so that A,B,C and D are always in order A-B-C-D (not necessarily together) is (A) 24 (B) 5040 (C) 210 (D) 720

Find the number of ways of arranging six persons (having A,B,C and D among them) in a row sothat A,B,C and D are always in order ABCD( not necessarily together).

The number of ways in which 7 persons can sit around a rond table is (A) 720(B) 360(C) 240 (D) 5040

Find the number of ways in which four particular persons A,B,C,D and six more persons can stand in a queue so that A always stands before B,B before and C before D.

6 persons A,B,C,D,E,F are arranged in row. Find the conditional probability that C&D are separated given that A o* B are together.6

24 : 60 : : 210 : ? (A) 504 (B) 343 (C) 336 (D) 330

There are 4 boys and 3 girls.Arrange the following in ascending order.a.Number of ways to arrange them in a row b.Number of ways to arrange them around a table c. Number of ways to arrange them in a row such that no two girls are together d.Number of ways to arrange them around a table such that all 3girls are together.

A,B,C and D have position vectors a,b,c and d, respectively, such that a-b=2(d-c). Then,

If a, b, c and d are four positive real numbers such that sum of a, b and c is even the sum of b,c and d is odd, then a^2-d^2 is necessarily