The same as for level 50 in any other skill: 101,333 xp. You can look this up in the runescape.wikia article about "experience". You can also right-click on a skill, and set a target; this will quickly show you how many xp you are missing for the selected target.
Take it to Pickupstix in, Taverly, (the summoning shop). You need level 20 summoning, in order for him to enchant the helm. Once it's enchanted, the Slayer helm will hold 50 scrolls.
you have to take your egg (which is obtained as a very rare drop from a brids nest random event) to and incubater which can be found in pickupstick's house in taverly you also need 50 something summoning (for exact number see summoning guide-then pets on the in-game guide to summoning skill)
around about 50.
101,333 xp.
it should not take over 1 day maybey 3-4 hours.
A LOT. :p
It really doesn't matter what skills they should have, as long as the combat skills are high enough to match that level such as like level 50+ Magic and level 50+ Range aything else other than the combat skill not inc. summoning matter.
50 Xp per ring made
You get 50 mining experience for every coal you mine.
50 Fishing XP 77 Cooking XP
i dont exactly know and i think they have around 500hp in the updated runescape and 50 i n the non updated runescape :L
I'm not exactly an expert on summoning, infact it is my lowest stat. all my stats are above 50 except for my summoning. My summoning level is 7. I haven't done summoning in a long time. BUT, if I do remember right, You just have to make summoning pouches. There may be other ways, Buut I can't remember, Sorry. I hope this helped a little bit. Peace, lolz