According to the Free Body Diagram of pulley system:
MA = W/T = n.
Here, MA is the mechanical advantage, W is the load, T is the tension, and n is the number of sections of rope supporting the load.
Let's calculate the ratio: 1700/340 = 5
Which means the T = 1/5 W, it can be achieved by compound pulley system with 4 or 5 pulleys.
So MA = 5, this is your answer.