I've heard all those before; they are really funny but they definitely pre-date Fed Ex.
Besides, Fed Ex is an American company and Americans spell tire with an "i".
That's a WWII / Korean War vintage set of jokes with some updates through the years, translated from American into the Queen's English.
Still a classic though. Another favorite:
There were 5 people in an airplane; the world's smartest man, the worlds richest man, the pilot, an old man and a little boy. All the engines were on fire and the plane was plummeting towards the earth but there were only 4 parachutes. So they started to argue about who would get a chute.
The world's smartest man said, "I get a parachute because I have many more things to discover", and so he grabbed a chute and jumped.
Then the world's richest man said he had many more things to buy and so he jumped with a chute.
The pilot said that he had many more planes to fly and he also grabbed a chute and jumped.
Now there was only the old man and the little boy with only one parachute left. The old man said to the little boy, "You go. I've lived a long life and after everything I've done I'm ready to die." The little boy said "That's okay, we can both jump; the world's smartest man took my back pack."
