A:I believe the key to this "problem" is to understand that a "day and a night" was an idiomatic expression for what we could a "day" in the 24-hour sense: a Jewish day composed of a night and the following day. Multiplying this expression by three converts "day and night" to "three days and three nights" but this does not imply that the nights must be counted separately from the days. They must be counted together, as three "day-night" units.

The Jewish way of counting days is inclusive to both ends, so if a boy is born on Tuesday of this week, he is circumcised on "the eighth day" meaning Tuesday of next week. To be dead for three "day-nights" means that if you die on Friday you have to stay dead through Saturday and can come back to life on the third day, which would be Sunday. This counts as three days and three nights in Hebrew. This may seem illogical, but human language often does. 

In any case, if I  met someone who said who said who would come back from the dead after three nights and three days, and I actually saw him die and come to life after what seemed to be only two nights and one day, I would be inclined to give him the benefit of the doubt.