hi Joe why did you multiply it with 2 in relative mass 27?
there are two ways to make B2H6 with mass 27
P(B¹⁰ B¹¹) + P(B¹¹ B¹⁰) = 0,16 + 0,16
Not 100% sure why we need to approach this question with probability and a tree diagram
just like Juliette says above, it kinda on stat aspect