First and . . .
 

A's ball 1st and goal at the 4. 2 plays and 2 sacks later it's 3rd down and goal from the 35. On 3rd down, B commits pass interference on an incomplete pass. Down and distance?

NFHS: 1st and 10 from B's 20. The penalty is 15 yards from the previous spot and an automatic first down.

What Rich said. :)

What he said

Amen.

Is this one of those NFHS trick questions?;)

NCAA: depends on where the DPI occurred. If within 15 yards, a spot foul. If more than 15 yards, 15 yards. Either way, first down and 10.

Sort of, almost, but not quite.

Does the fact that this occurred under Fed Rules during overtime change anything?

That depends on which state this happened in. In some states it's possible to have first and ten so this play could be 1/10 from the 20. My state uses the NF OT so it would be 1/Goal from the 20.

Actually, I started to mention OT. However, how did it get to be A's ball 1st and goal at the 4? I guess there are ways but it's kinda weird.

Wouldn't matter here in WI. We start at the 25 and use the chains in OT.

Ball was at the 8 yard line, pass interference by the defense. I wouldn't say that is weird. Weird would be a blocked field goal muffed by B beyond the neutral zone which then rolls back behind the neutral zone, recovered by A and advanced to the 4 yard line.

Canadian Ruling
 

CANADIAN RULING:

Team A 1D/10 @ PLS if the PF is < PLS.
Team A 1D/10 @ PF if the PF is < 15y from PLS.
Team A 1D/10 @ B-20 if the PF is > 15y from PLS.