A metal piece weighs 200gf in air and 150 gf when completely immersed in water.
Calculate the relative density of the metal piece.

Explanation

To calculate the relative density of the metal piece, we can follow these steps:

### Step 1: Identify the weights
- Weight of the metal piece in air (W_air) = 200 gf
- Weight of the metal piece in water (W_water) = 150 gf

### Step 2: Calculate the loss of weight in water
The loss of weight when the metal piece is immersed in water can be calculated as:
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