Lotteries

[jack]

Your chances of winning a scratch and win is 1:5

How do I say that? Is it this:
1. My chances of winning a sractch and win are one in five.

Your chances of winning a scratch and win is 1:50

For this, is it:
2. My chances of winning a sractch and win are one in fifty.

Thanks.

[Mister Micawber]

All fine in casual conversation, Jack, but I think the better part of valour would be to rephrase as:

My chance of winning a scratch-and-win is one in fifty / one in five.