I have held this stock for sometime now, just need to clarify...

I have held this stock for sometime now, just need to clarify some points re this take over offer. Unfortunately I hold another stock (BRM) where the T/O has turned into a complete farce, and very stressful. I just don't want to get any of the facts mixed up. This little brain of mine can only cope with so much information at any one time.

1. Offer is 57c per share, due in May.
What percentage do they need to acquire to take over the company? What happens if a holder does not accept that price?

2.Will they continue to be listed on our exchange, or is that it?

Thanks for your help.

Cheers

G6