Let represent the amount of money Tina, Dawn, and Harry have respectively.

So we know that

-- (1)

-- (2)

-- (3)

Subbing (3) into (2), we can see that

-- (4)

Now substitute (4) and (3) into (1) to get

Thus, and

(Note that when we go to check our answer, we have due to rounding errors.)

Does this make sense?