Translation:It is 3:03.
By itself, I believe it is spelled "fun" in Romaji. But the Japanese "f" is actually in between the English "f"and "h", and may sound a little more like "h". However, in this exercise it's sanpun, sounds like a "p", because it changes to a p for several of the numbers of minutes, as other posts have indicated.
So when does 分 change from ふん、ぶん to ぷん. I read a comment from someone who has noticed that some even/odd pattern exists. But it feels like that might be a coincidence and might not hold further up the number line. Does anyone have some documentation or is it just one of those quirks you have to learn?
It is ぷん with 1, 3, 4, 6, 8 and 10 minutes
There isn't a strict rule to when rendaku happens with counters so often you'll just have to learn them as you go. There are usually some commonalities though which will make it a bit easier.
四分・よんふん or よんぷん
八分・はっぷん or はちふん
Note that some numbers (like 4 and 8) can be read with or without rendaku due to natural language shift (though with rendaku is more traditional).
The reading ぶん "bun" is not used for time, it is actually the counter for parts
三分・さんぶん・ three parts
十分 じゅっぷん"juppun" is "10 minutes"
十分 じゅうぶん "juubun" means "sufficient/enough" or "ten parts" (10 out of 10 is a whole)
This is the reading that is used for 半分 hanbun "half (of something)"
but with the minute ぷん reading; 半分 hanpun "half a minute"
My sensei told me that ぷん or ぶん simply depends on whether it is more natural/comfortable for your mouth to transit from the previous syllable. Eg. いっぷん is more natural to pronounce than いっぶん. Not sure if that is really true but it made it more intuitive for me rather than to hard memorise ぷん or ぶん.