Well, the brand/materials/design matter quite a bit. I used diadarrios for ages and reallystruggled to get the tension. I was up to a 64 for the B when I switched to newtone thick cores and 60 was fine, and I tried the DR Tites with the 56 and found that they feel a little slacker, but sound punchier and tighter (smoother top end as well, if a tad dark).
With the DRs and newtones I used 12 15 20, I think, but the DR plains are a shade slacker so I'm happy with the 13....dont remember the other two.
I wouldnt use them on 24.75; too slack.