> 1. Julia has two sisters. That means there are three girls in total (Julia + two more). False. Julie could be the name of a boy. > 2. Julia also has one bro

> 1. Julia has two sisters. That means there are three girls in total (Julia + two more). False. Julie could be the name of a boy. > 2. Julia also has one brother, named Martin. OK > 3. Altogether, there are four siblings: three girls and one boy (Martin). Where did you identify the third girl? > 4. From Martin’s perspective, his sisters are all three of the girls (Julia and her two sisters). Here's where the answer comes from (Julia and her two sisters). More directly: "How many sisters does her brother Martin have?" > 5. Therefore, Martin has three sisters. OK. So the reasoning might have come to the "right" answer but the way it arrived at the answer was incorrect.