hello thank u so much.
if it was 3 brothers + 3 sisters, it should have been worded like this: 3 brothers + 3 sisters!
By saying 3 brothers and sisters is not clear as it should be. That is why I wrote
"so including him they are 4 children in the family"
a word problem should be absolutely clear to have a clear answer (solution)
thank you very much again
With best regards