Rob owns 5/9 of the stock in a local bread company. His sister Talia owns half as much stock as Rob. What part of the stock is owned by neither Rob nor Talia?

The part of the stock owned by others is 3/18

Step-by-step explanation:

Rob owns 5/9 of the stock

And Talia half as much as Rob then Talia has:

(5/9) : 2 = 5/18 of the stock

So Rob and his sister they both have

5/9 + 5/18 = (10 + 5) / 18 ⇒ 15/18

And the part of the stock owned by others is:

The total stock in term of fraction is 18/18 o 1 or 100 %

Then (18/18) - (15/18) = 3/18