The probability of first two children being boys is assuming each child arrives independently.
Hey, thanks for taking the time to reply.
I am not big on Maths, and am doing this as a small part of my Sociology course (Statistics), but the answer you gave is exactly the same answer that I gave, 33/41. I thought it might be wrong when I wrote it but wanted to write something rather than nothing.
It is marked wrong. So are we sure that is the right answer?