3:80+300-200

To solve the expression \(3:80 + 300 - 200\), we need to interpret the notation correctly. The notation "3:80" typically means \( \frac{3}{80} \) in mathematics.

Now, let's solve it step by step:

1. Calculate \( \frac{3}{80} \): \[ \frac{3}{80} = 0.0375 \]

2. Add 300 to this result: \[ 0.0375 + 300 = 300.0375 \]

3. Finally, subtract 200 from this sum: \[ 300.0375 - 200 = 100.0375 \]

So, the final result is: \[ 100.0375 \]