True or False:
If some or all of n objects are taken at a time, the number of combinations is `2^n -1`

Let n(A) = n, then the number of all relations on A, is

If a denotes the number of permutations of (x+2) things taken all at a time, b the number of permutations of x things taken 11 at a time and c the number of permutations of x-11 things taken all at a time such that a=182b c , find the value of xdot a) 10 b) 12 c) 15 d) 18

If a denotes the number of permutations of (x+2) things taken all at a time, b the number of permutations of x things taken 11 at a time and c the number of permutations of x-11 things taken all at a time such that a=182b c , find the value of xdot

True or False All monerans are autotrophs.

True or False Ecophene has a specific gene combination

True of False : Flux combines with slag to form gangue.

Find the number of permutations and combinations if n = 12 and r = 2.

True or False statements : Let N be the set of natural numbers. Then, the binary operation * on N defined as a * b = a + b for all a , b in N has the identity element.

Statement-1 If a set A has n elements, then the number of binary relations on A = n^(n^(2)) . Statement-2 Number of possible relations from A to A = 2^(n^(2)) . (a) Statement-1 is true, Statement-2 is true, Statement-2 is a correct explanation for Statement-1 (b) Statement-1 is true, Statement-2 is true, Statement-2 is not a correct explanation for Statement-1 (c) Statement-1 is true, Statement-2 is false (d) Statement-1 is false, Statement-2 is true

If ""^nC_r denotes the number of combinations of n things taken r at a time, then the expression ""^nC_(r+1)+""^nC_(r-1)+ 2xx""^nC_r equals :