"At neck edge, bind off 10 stitches once, 5 stitches once, while at the same time, at armhole edge, bind off 2 stitches twice, bind off remaining stitches"
1. Why bind off 10 then 5 - why not just bind off 15 stitches?
2. "while at the same time" - I have no idea how to knit in two places at once. Clearly I missed this class, anywhere to read or see a video about it?
3. Why would I bind off 2 stitches twice and then bind off remaining. Why would I knot just bind off two stitches at once to the end. And why only twice?
1. They want the decrease to be a bit more gradual than 15 at once. Since you only bind off at the beginning of the row, there will be a row of purl between the two decreases--more of a stepped decrease rather than straight bind off.
2. 'At the same time' means that you'll be decreasing at both ends. On the knit side, you'll be binding off for the neck; on the purl side you'll bind off for the sleeves.
3. Again, you'll be binding off in steps, bind off 2, finish row, work back, bind off 2, finish row work back, bind off remaining.