TCS
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Numerical Ability
Probability
1. Three terrorists are employed to shoot a renowned person Mr. X. Only one bullet is sufficient to kill him if it strikes in the head. The probabilities of the terrorists striking Mr. X’s head by their bullets are 0.2, 0.3, and 0.4. What is the probability that Mr. X is shot dead?
(A) 0.336 (B) 0.9 (C) 0.1 (D) 0.760 (E) 0.664
Read Solution (Total 6)
-
- X will kill if at least one terrorist shot.let A,B,C are 3 terrorist
possible ways are.(A shot B and C not shot,B shot A and C not shot,c shot A and B not shot,A and B shot C not shot,B and C shot A not shot,A and C shot B not shot,A and B and C shot).
now
probability of A,B,C for not kill is .8,.7,.6
(.2*.6*.7+.8*.3*.6*+.8*.7*.4+.2*.3*.6+.2*.4*.7+.8*.3*.4+.2*.3*.4)
=.664 - 14 years agoHelpfull: Yes(33) No(4)
- probability of Mr. X shot dead = prob of atleast one terrorist shoot on head. = 1-prob of none shoot on head.
=1-0.8*0.7*0.6
=.664 - 12 years agoHelpfull: Yes(28) No(0)
- probabilities are 0.2 , 0.3 , 0.4
probabilities of not killing = (1 - 0.2) * (1 -0.3) * (1-0.4)
= 0.8 * 0.7 * 0.6
=0.336
probability of killing = 1 -(0.336)
= 0.664
option e
- 10 years agoHelpfull: Yes(4) No(0)
- (E) 0.664
- 14 years agoHelpfull: Yes(1) No(3)
- let the 3 terrorists be A, B and C
probability that X will b shot dead is:
A+(not A)B+(not A)(not B)C
here,
A=0.2
not A =0.8
B=0.3
not B= 0.7
C=0.4
not C=0.6
therefore:
0.2+(0.8)(0.3)+(0.8)(0.7)(0.4)
= 0.2+0.24+0.224
=0.664 - 9 years agoHelpfull: Yes(0) No(0)
- probability that none shots Mr.X=(1-0.2)*(1-0.3)*(1-0.4)=0.336
now probability Mr.X is killed=(1-probability that Mr.X is not killed)=1-0.336=0.66 - 9 years agoHelpfull: Yes(0) No(0)
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