4:2

It seems like you provided a ratio or a fraction (4:2), which can be simplified.

To simplify the ratio 4:2:

1. Divide both numbers by their greatest common divisor, which is 2.
2. \(4 ÷ 2 = 2\) and \(2 ÷ 2 = 1\).

So, the simplified ratio is 2:1.

If you meant something else or have a specific context in mind, please provide more details!