147 — sorry I am replying a year later; I don’t frequent the Coffee Room!
I don’t have a solution for Asara b’teves on erev shabbos — but it doesn’t happen often! I guess the best in that case is kiddush, hamotzi, and drink water, sing zmiros, and then eat more?
What is the problem with Y.K. / Tisha B’av on Sunday? I guess it is an issue for the one making havdola? Is that what you mean? First of all, if you make kiddush/havdolah on grape juice I think it is less of a problem. In any case, drink lots of water right after the wine/grape juice.
Also, my husband said (I don’t know if this is universal) that it is OK to drink water (just plain water, no other eating/drinking) before havdola on motzai shabbos; that should then be fine on motzai tisha b’av on Sunday as well. Not sure about Y.K. – I don’t think I’ve ever done that…..or thought to ask…..