1. Valid. The statement shows that if rock comes from Venus, it doesn't contain silicon. Rocks came either Mars or Venus. SO when rock contains silicon, it came from Mars not Venus.
(If Venus, then NOT silicon)
(Venus OR Mars)
(Silicon)
(Mars; Valid)
2. Invalid. It is not true that people with happiness must have a lot of money. The first premise is a false premise. Secondly, it is not true that people earn a lot of money with hard working. The second premise is also a false premise. Therefore this is an invalid statement.
