Per sachet = 41.2g carbs. is the value you are interested in.
... assuming you are going to eat the full contents of the sachet. The per 100g value is given purely to tick the nutritional guidelines so that people can easily compare products against each other, and the fact it weighs 244g "when wet" is irrelevant in this case, as the water you are adding has no nutritional value. HtH, Paul
It's confusing because the per 100g value is for the cooked final product. The "per sachet" is the value to use as the this is the same cooked and dry because of course water has no carbs.
There's lots of products that mix and match cooked and dry values, it's pretty annoying sometimes, especially when they say things like "1 portion = 3/18th of a pack"
Unfortunately that's often the intention. If the nutritional content isn't "ideal" then all sorts of sneaky convolutions may be used on packaging to hide such facts.
Sometimes the "per 100g" information can be useful as a base figure for calculations if you want to weigh and use differing amounts of a product.