Three old ladies
Three old, mischievous grandmas were sitting on a bench outside a nursing home.
About then, an old grandpa walked by and one of the old grandmas yelled out saying, "We bet we can tell exactly how old you are."
The old man said, "There ain't no way you can guess that, you old fools."
One of the old grandmas said, "Sure, we can! Just drop your pants and undershorts and we can tell your exact age."
Embarrassed just a little, but eager to prove they couldn't do it, he dropped his drawers.
"First, turn around a couple of times and jump up and down several times," the grandmas yelled.
Feeling totally foolish, but still anxious to prove the grandmas wrong, the old man complied with their orders.
"You're 87 years old!", the old ladies hooted.
Standing with his pants down around his ankles, the old gent asked, incredulously, "How in the world did you guess?"
Slapping their knees and grinning from ear to ear, all three old ladies happily yelled in unison, "We were at your birthday party yesterday!"