A police man is driving down the road when all of the sudden the freeway starts to get backed up. Not long after, he finds himself stuck in traffic going about 20 miles an hour. So he drives up around the traffic to see what the problem was.
When he gets to the front, he sees 3 nuns driving in a car at about 20 miles an hour. So he pulls them over and lets the traffic get by. He then asks them "Do you know the speed limit."
They answer, "Yes" and they point towards the 22 freeway sign and say "We were going 22 miles per hour.
The policeman shakes his head and says, "No, that's the freeway sign... the speed limit sign is over there." And with that he points to the correct MPH sign.
"Ohhh..." said all of the nuns until the nun in the back starts cracking up.
"What's wrong" asks the police man...
The nun replies, "Well, you should have seen us yesterday on the 135!"