Let, Probability of choosing a copper coin overall= P(C)
Probability of choosing a copper coin From bag A= P(A)
Probability of choosing a copper coin From bag B= P(B)
Probability of choosing a Bag= 1/2
P(C)=1/2 x P(A) + 1/2 x P(B) = 1/2 x 4/7 + 1/2 x 6/10 = 41/70