2:[2+5]*20

To solve the expression \(2:[2+5]*20\), we need to follow the order of operations.

1. Evaluate the expression inside the brackets: \[ 2 + 5 = 7 \]

2. Substitute back into the expression: \[ 2 : 7 * 20 \]

3. Note that ':' often represents division, so we can rewrite it as: \[ \frac{2}{7} * 20 \]

4. Now perform the multiplication: \[ \frac{2 * 20}{7} = \frac{40}{7} \]

5. To get a decimal approximation: \[ \frac{40}{7} \approx 5.71 \]

So, the final result of the expression \(2:[2+5]*20\) is: \[ \frac{40}{7} \text{ or approximately } 5.71. \]