D. 21/40
Feedback Let A be the event that ball selected from the first bag is red and ball selected from the second bag is green.
Let B be the event that ball selected from the first bag is green and ball selected from the second bag is red.
P(A)=(5/8)×(6/10)=3/8 and P(B)=(3/8)×(4/10) =3/20
Hence, required probability,
=P(A)+P(B)
=3/8+3/20
=21/40