Most Important Selected Qs for JEE AdvancedMathematicsProbability
A man has 3 coins A, B and C, A is unbiased, the probability that a head will result when B is tossed is 2 3 , the probability that a head will result when C is tossed is 1 3 . One of the coin chosen at random and is tossed 3 times, giving a total of two heads and one tail. ( array ll Column-I & Column-II (A) The probability that the chosen coin was A & (p) 32 75 (B) The probability that the chosen coin was B & (q) 1
Options
- A( A ) ( q ) ;( B ) ( t ) ;( C ) ( p ) ;( D ) ( s )
- B( A ) ( p ) ;( B ) ( s ) ;( C ) ( q ) ;( D ) ( t )
- C( A ) ( s ) ;( B ) ( p ) ;( C ) ( q ) ;( D ) ( q )
- D( A ) ( t ) ;( B ) ( q ) ;( C ) ( p ) ;( D ) ( s )
Correct answer
C. ( A ) ( s ) ;( B ) ( p ) ;( C ) ( q ) ;( D ) ( q )
Step-by-step solution
Let E be the event of getting 2 head and I tail aligned & P(A)=P(B)=P(C)= 1 3 & P(E / A)= ^3 C₂ ( 1 3 )^2= 3 8 P(E / B)= ^3 C₂ ( 2 3 )^2 ( 1 3 )= 4 9 & P(E / C)= ^3 C₂ ( 1 3 )^2 ( 2 3 )= 2 9 aligned So by Baye's theorem P ( A / E )= 9 25 , P ( B / E )= 32 75