Raid 1 question 3 hds

Can you have 3 hds in raid 1? Will the write speed be decreased in 3 vs 2 hds? Will the read speed be increased with 3 vs 2 hds?

No, the RAID controllers I have seen only supports 2 disks in a RAID 1 configuration. You could consider a RAID 5, if the disks have the same sizes.