Which would you say? and are they correct grammatically?

1 Don't eat while playing/Don't play while eating

The playing is longer than the eating??

2 He hates me just as I hate him./just like I hate him.

3 It'll cost you more to fix zipper than the cost of the jacket.

4 He's richer at 24 than me when I was 40.

5 I a little more than tripled my investment. (Is this how you'd say it?)

thank you
1. I'm not sure what you wanted to ask here.

But if you are having lunch and she is playing, you say:

Don't play while eating!

If she is playing on the piano and eating something, you say:

Don't eat while playing!

2. He hates me just as I hate him. This is fine

3. OK (the zipper)

4. OK

5. I think this sentence is Ok, though sounds a bit weird, but I can't think of a better way to say it.

I tripled my investment - is definitely correct. So you can also say:

I more than trippled my investment.

I a little bit more than tripled my investment.

I guess it sounds weird because 'a' usually doesn't follow pronouns.

But the more I think about it, the less I know it Emotion: smile
Could someone else give me their opinion on these please?

Thank you