A DOCTOR HAVE A BROTHER BUT THE BROTHER DID NOT HAVE BROTHER RIDDLES WITH ANSWERS TO SOLVE - PUZZLES & BRAIN TEASERS

Zero. If read to grammatical perfection, the riddle uses the word 'had' in a pas-tense format which means he no longer has children.

Therefore all of the daughters and brothers could be from a prior marriage, affair etc. Although, again, the riddle doesn't not specify that the brothers are 'step brothers.' Did you answer this riddle correctly?
YES  NO  

Seven (DAD + MOM + FOUR DAUGHTERS + 1 SON) Did you answer this riddle correctly?
YES  NO  

There are nine Mustards in the family. Since each daughter shares the same brother, there are six girls, one boy and Mr. and Mrs. Mustard. Did you answer this riddle correctly?
YES  NO  

Mary has four daughters. Let x be the daughter.
Four daughters mean - x + x + x + x
Each of her daughters has one brother - let y be the son.
Total children => x + x + x + x + y. => 5
She has Total 5 children, all of her daughters have the same 1 brother. Did you answer this riddle correctly?
YES  NO  

An apple a day keeps the doctor away. Did you answer this riddle correctly?
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Lemon aid! Did you answer this riddle correctly?
YES  NO  

Tweet-ment Did you answer this riddle correctly?
YES  NO  

Unhoppy! Did you answer this riddle correctly?
YES  NO  

To the witch doctor! Did you answer this riddle correctly?
YES  NO  

To the dock! Did you answer this riddle correctly?
YES  NO  

When God gave Moses two tablets. Did you answer this riddle correctly?
YES  NO  

Oink-ment! Did you answer this riddle correctly?
YES  NO  

A slow-poke. Did you answer this riddle correctly?
YES  NO  

A cold Did you answer this riddle correctly?
YES  NO  

The taste. Did you answer this riddle correctly?
YES  NO