This guide will show you the mathematical equation in order to get the answer you're looking for. Please take note that this is under progress and will continuously be updated and if they are questions that i'm missing out, please feel free to pm me and I will answer it here.
How many games does it take to get full void? = (Total cost of void) / (number of points per game) = number of games
How long will it take for me to get full void = (average game length in seconds) / (number of points per game) = (Number of seconds it takes to get a point) x (total cost of void) = How long it will take. Then just divide by 60 for answer in minutes, then divide 60 again for number in hours
How many *insert item name* do I need to get 99 in *insert skill* = (13,034,431) - (Current exp) = (Remaining exp till that level) / (exp per *insert item*) = (# of item you'll need to get 99)
How much will this skill cost from this level to that level? = (Xp of skill level that you wanna get) - (Current exp) = (remaining exp till that level) / (exp per fish/gem/etc) = (How many you need to get to that certain lvl) x (price of item) = Cost
How long will it this skill to go from this level to that level? = (Xp of skill level that you wanna get) - (Current exp) = (remaining exp till that level) / (exp per fish/gem/etc) = How many you need to get that certain lvl.
(Number of seconds it takes to finish an inventory) / (how many items in your inventory) = (How many seconds it takes to craft/fish/mine,etc 1 item) x (How many you need to get that certain lvl) = How long it'll take. then divide 60 to get an answer in minutes and divide 60 again to get the answer in hours.
How much more exp will I get from using a vote book(Only works for non combat skills) = (0.5) x (exp without bonus xp) = (50% of the regular exp) + regular exp = how much more exp you'll get doing that certain activity
How much more exp will I get from well of goodwill? = (0.5) x (exp without bonus xp) = (50% of the regular exp) + regular exp = how much more exp you'll get doing that certain activity
How much more exp will I get from Bonus exp of the day? = (0.3) x (exp without bonus xp) = (30% of the regular exp) + regular exp = how much more exp you'll get doing that certain activity
Pest control points without bonus:
Normal = 3
Reg don = 4
Super = 5
Extreme = 6
Legendary = 7
Uber = 8
Master = 9