American Jokes

Three blond girls come into a bar chanting "Sixty-one days, sixty-one days...". The waiter finds that interesting and asks what is going on, so one of the girls says "We finished a jigsaw puzzle picture in sixty one days!" and the waiter insists "Ok but, why are you chanting this?" The other blond replies "Cause the box says three to six years."

What did the waiter ask to a horse that came into the bar? "Why the long face?"

"Why is 6 afraid of 7? Because 7 8 9."

Can you realize the cultural elements in these jokes? Are they funny for you?Is it possible to translate a joke from portuguese to english?Is it still funny?