Question 21 Mark${ }^{43} C _{r-6}={ }^{43} C _{3 r+1}$ then the value of $r$ is __________.Answer$12$View full question & answer→
Question 31 Mark${ }^n C _x^{}={ }^n C _y \Rightarrow$ ________ or ________.Answer$x=y, x+y=n$View full question & answer→
Question 51 Mark${ }^n C _r+{ }^n C _{r-1}=$ __________.Answer${ }^{n+1} C_r$View full question & answer→
Question 61 MarkThe number of combinations made of $r$ objects at a time out of $n$ different objects is _________.Answer${ }^n C _r$View full question & answer→
Question 71 MarkThe number of permutations made from $n$ different objects taking $r$ objects at a time, while repetition of objects is allowed is _________.Answer$n^r$View full question & answer→
Question 81 MarkThe number of permutations made by taking $r$ objects at a time out of $n$ different objects is ________.Answer${ }^n P _r$View full question & answer→
Question 91 Mark_________ is an arrangement made in a certain order, which is made by taking some or all of the given items at one time.AnswerPermutationsView full question & answer→
Question 101 MarkIf an incident may happen in $n$ different ways, followed by another incident can occur in $n$ different ways, then the total number of different ways in which both the events can occur in the given sequence is ________.Answer$m \times n$View full question & answer→