2. Sample Papers
  3. JEE Main & Advanced

JEE Main & Advanced Sample Paper JEE Main - Mock Test - 17

  • question_answer
    When a missile is fired from a ship, the probability that it is intercepted is 1/3. The probability that the missile hits the target, given that it is not intercepted is 3/4. If three missiles are fired independently from the ship, the probability that all three hits their targets .is

    A) \[1/12\]                  

    B)        \[1/8\]          

    C)     \[3/8\]                           

    D) \[3/4\]

    Correct Answer: B

    Solution :

            [b] Let, Event R: Missile is intercepted Event H: Missile hits the target Then, \[P(R)=\frac{1}{3};\]   \[P(\bar{R})=\frac{2}{3}\] \[P(H)=P(H\cap R)+P\left( H\cap \bar{R} \right))\]             \[=P(R).P(H/R)+P(\bar{R}).P(H/R)\] \[=\frac{1}{3}\times 0+\frac{2}{3}\times \frac{3}{4}=\frac{1}{2}\] \[\therefore \,\,P(H\,\,H\,\,H)=\frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}=\frac{1}{8}\]


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