Question 151309
Snakes have no feet so the 56 feet must belong to the colection of iguanas, and, since each iguana has 4 feet, there are 56/4 = 14 iguanas.
Each iguana has two eyes, so the 14 iguanas have 28 of the 50 eyes, leaving 22 eyes for the snakes, and each snake has two eyes, so there must be 22/2 = 11 snakes.