Two urns contain colored blocks. The first contains three blue and two green blocks. The second contains four green and six blue blocks. An urn is selected and then three blocks are selected, one...

Two urns contain colored blocks. The first contains three blue and two green blocks. The second contains four green and six blue blocks. An urn is selected and then three blocks are selected, one green and two blue.
What is the probability that the selected urn was the first?