about to only mathematics

Answer

A, B

Explanation

Given, `P(A)=" probability that A will hit "B=(2)/(3)`
`P(B)=" probability that B will hit "A=(1)/(2)`
`P(C)=" probability that C will hit "A=(1)/(3)`
`P(E)=" probability that A will be hit "`
`impliesP(E)=1-P(bar(B)).P(bar(C))=1-(1)/(2).(2)/(3)=(2)/(3)`
Probability if A is hit by B and not by C
`=P(Bnnbar(C)//E)=(P(B).P(bar(C)))/(P(E))=((1)/(2).(2)/(3))/((2)/(3))=(1)/(2)`