Page 165 - Engineering Mathematics Workbook_Final
P. 165

Probability & Statistics

            1.     Suppose A and B are two                        4.     Two players, A and B, alternately
                   independent events with probabilities                 keep rolling a fair dice. The person to
                   P A             P B                                 get a six first wins the game. Given
                     ( ) 0  and  ( ) 0 . Let  A  and
                                                                         that player A starts the game, the
                   B  be their complements. Which one                    probability that A wins the game is
                   of the following statements is
                   FALSE?                                                    5                     1
                                                                         (a)  11               (b)   2
                            
                       P
                   (a)  ( A B =  )  P A P B
                                      ( ) ( )
                                                                             7                     6
                                )
                       P
                   (b)  ( | A B =  P ( ) A                               (c)  13               (d)  11
                                 )
                            
                       P
                                               ( )
                   (c)  ( A B =     P ( ) A +  P B                                   [GATE-2015-EE-SET-1]
                                      ( ) ( )
                         (
                                 )
                             
                   (d)  P A B =     P A     P B                  5.     Ram and Ramesh appeared in an
                                                                         interview for two vacancies in the
                                                                         same department. The probabilities of
                               [GATE-2015-EC-SET-1]
                                                                         Ram’s selection is 1/6 and that of
            2.     Three vendors were asked to supply a                  Ramesh is 1/8. What is probability
                   very high precision component. The                    that only one of them will be

                   respective probabilities of their                     selected.
                   meeting the strict design                             (a) 47/48             (b) 1/4
                   specifications are 0.8, 0.7 and 0.5.
                   Each vendor supplies one component.                   (c) 13/48             (d) 35/48
                   The probability that out of total three
                   components supplied by the vendors                 [GATE-2015-EC-SET-2; ME - SET-1]
                   at least one will meet the design              6.     Two coins R and S are tossed. The 4

                   specifications is __________.                         joint events  H H , T T , T H
                                                                                            S
                                                                                                R S
                                                                                        R
                                                                                                          S
                                                                                                       R
                                            [GATE-2015]                  have probabilities 0.28, 0.18, 0.30,
                                                                         0.24 respectively, where H represents
            3.     If P(X) = 1/4, P(Y) = 1/3 and                         head and T represents tail. Which one
                   P ( X   Y ) 1/12=  , the value of                    of the following is TRUE?
                   P(Y/X) is
                                                                         (a) The coin tosses are independent

                       1                      4
                   (a)                   (b)                             (b) R is fair, S is not
                       4                     25
                                                                         (c) S is fair, R is not
                       1                     29
                   (c)                   (d)                             (d) The coin tosses are dependent
                       3                     50

                                                                                     [GATE-2015-EE-SET-2]
                   [GATE-2015-ME-SET-3; 1 MARK]



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