Question: I have seen one form of using *avoir*, recently, like this: **à avoir eu**.

I forgot the phrase itself, but, for example in this phrase I just found in Google:

> 
> Les jeunes de l’OM sont 2 sur 14 à avoir eu le bac cette année.
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What kind of form is it? When/Where it supposed to be used?..

Answer: 
This *à* is a preposition and is not part of the verb form. This sentence is based on the construction “***être*** [un certain nombre] **à**” like in:

> 
> Ils **sont** 3 sur 4 **à** regarder la télé plus de trois heures par jour.  
> 
>  Ils **sont** plus de la moitié **à** regretter son départ.
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This preposition is then followed by a verb in infinitive form. In French an infinitive can be given an “accomplished aspect” (*aspect révolu*), which is formed using the appropriate auxiliary verb (it depends on the main verb) and the past participle. In your case “*avoir*” becomes “*avoir eu*”. Other examples:

> 
> Elle se rappelle *avoir marché* sur les Champs Élysées.  
> 
>  Il pensait *avoir résolu* le problème.  
> 
>  Ils croient *être allés* sur Mars.
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And in passive form:

> 
> Il croyait *avoir été compris*. 
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You can translate it word by word to “to have had”, and as far as I can tell, it has the same meaning.

*Avoir eu* is called the [**past infinitive**](http://french.about.com/od/grammar/a/pastinfinitive.htm) of *avoir*, and “indicates an action that occurred before the action of the main verb, but only when the subject of both verbs is the same.”

The second part of it is *“être quelques-uns à faire quelque chose”*, which does not translate very well in English, but means “those who did this (or to whom this happened) were, say, a few”.

Here, “they were 2 out of 14 to pass the exam” seems not so poorly said. (Or “… to have received their diploma”, to stick to the french construction)