Merge pull request chiphuyen#32 from rrrohit1/master

typo in section 7.3

contents/7.3-objective-functions,-metrics,-and-evaluation.md

@@ -79,7 +79,7 @@
 
 > The first shelter has only dogs. Your mom covers your eyes when your dad picks out an animal for you. You don't need to open your eyes to know that this animal is a dog. It isn't hard to guess.
 
-> The second shelter has both dogs and cats. Again your mom covers your eyes and your dad picks out an email. This time, you have to think harder to guess which animal is that. You make a guess that it's a dog, and your dad says no. So you guess it's a cat and you're right. It takes you two guesses to know for sure what animal it is.
+> The second shelter has both dogs and cats. Again your mom covers your eyes and your dad picks out an animal. This time, you have to think harder to guess which animal is that. You make a guess that it's a dog, and your dad says no. So you guess it's a cat and you're right. It takes you two guesses to know for sure what animal it is.
 
 > The next shelter is the biggest one of them all. They have so many different kinds of animals: dogs, cats, hamsters, fish, parrots, cute little pigs, bunnies, ferrets, hedgehogs, chickens, even the exotic bearded dragons! There must be close to a hundred different types of pets. Now it's really hard for you to guess which one your dad brings you. It takes you a dozen guesses to guess the right animal.