The least possible Venn diagram for the given statements is as below,
Conclusions: 1. Some frogs are snakes → True (It is clear from the given statement that all the snakes are frogs that means some frogs also be snakes will be true). 2. Some monkeys are cat → False (It is clear that some frogs are monkeys and vice versa but there is no direct relation given between monkeys and cats so we can't surely comment anything about this). 3. All cats are snakes → False (It is clear that all snakes are cats but we can't say that all the cats are snakes because no direct relation given from the cat side). Thus, Only conclusions I follow.