If x=3n,where n is a positive integral value, then what is the probability that x will have 3 at unit’s place? 

If x=3n,where n is a positive integral value, then what is the probability that x will have 3 at unit's place? 

  1. A

    13

  2. B

    14

  3. C

    15

  4. D

    12

    Register to Get Free Mock Test and Study Material

    +91

    Verify OTP Code (required)

    I agree to the terms and conditions and privacy policy.

    Solution:

    We have 

        31=3,32=9,33=27,34=81,35=243,36=729  etc. 

    So, a natural number of the form 3n may have either

     3 or 9 or 7 or 1 at unit's place. 

         Total number of elementary events= 4

     Clearly, only one number has 3 at unit's place. 

      Favourable number of ways = 1 

    Hence, required probability= =14 

    Chat on WhatsApp Call Infinity Learn

      Register to Get Free Mock Test and Study Material

      +91

      Verify OTP Code (required)

      I agree to the terms and conditions and privacy policy.