Answer: $195
Explanation:
Let x be the amount of money (in dollars) saved by Brett.
Then, the amount saved by Dan = 2x
The amount saved by Maria = 60+x (1)
If they saved $600 altogether, then we have the following equation :-

Divide both sides by 3, we get

Now, the amount saved by Brett = $135
The amount saved by Maria = $135+$60 = $195 [From (1)]