# Math for Computer science Questions and Answers 261 to 270

## Math for Computer science

### Questions 261 to 270

 261 “If it is rainy, then the pool will be closed. It is rainy. Therefore, the pool is closed.” The rule of inference used is ­­­­_________. (a)  Addition                                          (b)  Simplification                        (c)  Modus ponens (d)  Modus tollens                                  (e)  Hypothetical syllogism. 262 The contrapositive of the implication given below        “I come to the class whenever there is going to be a quiz.” (a)   If there is going to be a quiz, I come to class (b)  If I come to class, there will be a quiz          (c)  If I do not come to class, then there will not be a quiz (d)  If there is not going to be a quiz, then I will not come to the class     (e)  If there is not going to be a quiz, then I will come to the class. 263 A is a subset of B but A  B then A is called ______ of B. (a)  superset           (b)  proper subset    (c)  power set          (d)  null set         (e)  sample set. 264 The name given to the rule of inference P(c) for an arbitrary c, xP(x) is (a)   Universal instantiation                      (b)  Universal generalization                    (c)  existential instantiation                     (d)  existential generalization                   (e)  Universal quantification. 265 Which of the following functions is not one-one defined over the set of positive integers? (a)  x2                     (b)  x–1                   (c)  x+1                   (d)  2x+1                 (e)  4x. 266 Let p(x) be the statement “x = x2”. If the universe of discourse consists of the integers which one of the following propositions is false? (a)  P(0)                                                (b)  P(1)                  (c)  xp(x)              (d)  For all p(x)                                       (e)  Both (a) and (b) are false. 267 The fallacy occurring when one or more steps of the proof are based on the truth of the statement being proved (a)   Fallacy of denying the hypothesis   (b)  Fallacy of affirming the conclusion  (c)  Fallacy of begging the question (d)  Fallacy of denying the conclusion (e)  Fallacy of affirming the hypothesis. 268 The set containing those elements that are in A but not in B where A and B are two sets is denoted by (a)  A  B              (b)  A  B              (c)  A  B              (d)  A  B              (e)  A – B. 269 Which of the following pairs of sets are equal? (a)  {1,3,3,3,5,5,5,5,5}, {1,3,5}                  (b)  {{1}}, {1,{1}}        (c)  , { }         (d)  (a) and (b)                                       (e)  (b) and (c). 270 The range of the function that assigns to a bit string the number of times the block 11 appears in the bit string. (a)  set of integers                                 (b)  set of whole numbers           (c)  set of real numbers (d)  set of all bit strings                          (e)  set of  irrational numbers.