Answer 3_3_3
Here's the circuit again:
First we will look at the parallel combination:
Add the 500 ohm and the 600 ohm resistors together to get 1100 ohms.
Now work out the single equivalent resistor for a 200 ohm and a 1100 ohm combination:
1 = 1 + 1 = 0.005 + 9.091 x 10-4 = 0.00591 ohm-1
Rtot 200 1100
Note how we have used the decimal reciprocals. Do this if you forget how to add common fractions!
Rtot = 1 = 169 ohms
0.00591
Did you fall into
the bear trap? 
Now we can find the total resistance of the circuit:
Rtot = 400 ohms + 169 ohms + 200 ohms = 769 ohms
Don't be scared of these circuits. Break them down and use the simple rules.