Clearly, the sample space is `S={1, 2, 3, 4, 5, 6, 7, 8, 9, 10}`.
Let `A =` event that the number on the drawn card is even, and `B=` event that the number on the drawn card is more than 3.
then `A={2, 4, 6, 8, 10}, B={4, 5, 6, 7, 8, 9, 10}`
and `A nn B={4, 6, 8, 10}`.
`:. P(A)=(n(A))/(n(S))=5/10=1/2, P(B)=(n(B))/(n(S))=7/10` and
`P(A nn B)=(n (A nn B))/(n(S))=4/10=2/5`.
Suppose B has already occurred and then A occurs.
So, we have to find `P(A//B)`.
Now, `P(A//B)=(P(A nn B))/(P(B))=((2//5))/((7//10))=(2/5xx10/7)=4/7`.
Hence, the required probability is `4/7`.