Policeman Vs Greengrocer

A greengrocer was cutting apples in his shop cut the apple out of his own shop (this line didn't translate well. Often in English, you use the past tense when you talk about something that happened in the recent past and is still happening). He kept the seeds, but and he threw throwed  (threw is the past tense of throw) the pulp.
A curious policeman asked him: "Why do you throw out the pulp?"
The greengrocer answered: "The seeds of the apples get  make people more clever"
policeman: "Oh, then give me 3 seeds. How much?"
greengroc: "15 euros"
policeman: "Ok." and then He ate it. (you could omit 'he' here too)
5 minuts later...
policeman: " Hey greengrocer, with 15 euros I can buy 9 kilos of apples and therefore dozens of seeds!!!"
greengrocer: "I told you! it works!"
policeman:"OOhh! You're right! Give me another 5 seeds!"

:-D
In italy the jokes about policeman (carabineri) is much used. In Italy it's very common to make jokes about policemen (this is closer to how an English person would say that sentence) 

We make similar jokes to this, but they are often about people with blonde hair (and typically women). Or often about people from rival or neighboring towns and cities. 

Policeman Vs Greengrocer

A greengrocer cut the apple out from his own shop. He kept the seeds and he threw the pulp away.
A curious policeman asked him: "Why did you throw the pulp away?"
The greengrocer answered: "The seeds of the apples make people cleverer"
Policeman: "Oh, give me 3 seeds. How much?"
Greengrocer: "15 euros"
policeman: "Ok." and he ate it.

5 minutes later...
Policeman: " Hey greengrocer, with 15 euros I can buy 9 kilos of apples and therefore dozens of seeds!!!"
Greengrocer: "I told you! it works!"
Policeman:"OOhh! You're right! Give me another 5 seeds!"

:-D

In Italy  jokes about policemen (carabineri) are very common.

Hello Francesco,

This was a new joke for me and I really liked it! Just a few small problems - you throw something away (buttar via?), you make sb + adjective or comparative.

We have a famous local joke here -

"How many policemen does it take to change a lightbulb?"

"5 - One to hold the bulb and four to turn the chair!!!"

Best wishes

Bob