J & K CET Engineering J and K - CET Engineering Solved Paper-2013

  • question_answer
    A bag contains 50 tickets numbered 1, 2, 3, ...,50 of which five are drawn at random and arranged in ascending order of magnitude \[({{x}_{1}}<{{x}_{2}}<{{x}_{3}}<{{x}_{4}}<{{x}_{5}}),\] then the probability that \[{{x}_{3}}=30\] is

    A)  \[\frac{^{29}{{C}_{2}}{{\times }^{20}}{{C}_{2}}}{^{50}{{C}_{5}}}\]

    B)  \[\frac{^{30}{{C}_{1}}{{\times }^{29}}{{C}_{1}}}{^{50}{{C}_{5}}}\]

    C)  \[\frac{^{5}{{C}_{1}}{{\times }^{50}}{{C}_{2}}}{^{50}{{C}_{5}}}\]

    D)  \[\frac{^{50}{{C}_{2}}{{\times }^{29}}{{C}_{1}}}{^{50}{{C}_{5}}}\]

    Correct Answer: A

    Solution :

    Let E= Event  of getting 5 tickets ascending order. Since, it is given that number 30 is on 3rd position. So we have to choose two numbers from 1 to 29 numbers and choose two numbers from 31 to 50 \[\therefore \] \[n(E){{=}^{29}}{{C}_{2}}{{\times }^{20}}{{C}_{2}}\] Total number of selection of 5 cards From 1 to 50 is, \[n(S){{=}^{50}}{{C}_{5}}\] \[\therefore \] Required probability \[=\frac{n(E)}{n(S)}=\frac{^{29}{{C}_{2}}{{\times }^{20}}{{C}_{2}}}{^{50}{{C}_{5}}}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner