Q.
In a combat, A targets B, and both B and C target A. The probabilities of A, B, C hitting their targets are 2/3,1/2 and 1/3 respectively. They shoot simultaneously and A is hit. the probability that B hits his target whereas C does not
E1:A targets B;P(E1)=32 E2:BtargetsA;P(E2)=21 E3:C targets A;P(E3)=31
Given A is hit. Hence H1:B hits A and C does not H2 : C hits A and B does not H3:B and C both hit A ∴P(H1)=21⋅32=31 P(H2)=31⋅21=61 P(H3)=31⋅21=31⋅21
now, P(H1/H1∪H2∪H3)=31+61+6131=21