6 cats equals 1 dog 2 dogs pig 8 pigs cow 3 plus 4 how many cows?

The answer is 2 cows. The riddle follows a formula in which each "level" up the animal scale consists of double the number of the previous level. For example, it takes 6 cats to equal 1 dog; 2 dogs to equal 1 pig; 8 pigs to equal 1 cow; therefore, it takes 2 cows to equal 1 "3 plus 4" (which equals 7).