Puzzle 135 - Who's who

 In a certain bank the positions of teller, manager and cashier are held by Jones, Smith and Brown, but not necessarily respectively. 

The teller is the only child and he earns the least.

Smith is married to Brown's sister and he earns more than the manager. 

What position does each man hold?

(This puzzle is from the book 101 puzzles in thought and logic by C.R.Wylie) 

  

Solution :

• As teller is the only child - Brown can't be teller. Teller earns the least, so teller can't be Smith as Smith earns more than manager.  So teller has to be Jones.
• Because Smith earns more than manager, Smith can't be manager. And he can't be teller as Jones is teller. So Smith must be cashier. 
• Brown who is the only one remaining should be manager.