Nobody knows the real numbers here, i'm just giving a sence of time required to acquire some items.
Truth be told, these numbers are based on feeling, and some math, in relation to days spent farming/loot dropped.
I certainly didn't make a record of my loot drop/times played.
To get as close to real number as we can, we need dosens of players recording their loot drop rate, and calculate the average. Even then its unreliable, because the math of random is tricky.
Pm won't tell us certainly the real odds, but since your skip button doesn't work, and i've been farming it for the past week or a bit longer, thats 600-650 tries, for you thats 2400 mins, calculating it takes you four minutes to finish a level, i'm quite sure you didn't spend 40 hours just farming third earth dragon, even through a month this would be exausting. And even then, your memory would be questionable, since its stretched over 1 month. The nuggets you dropped are real though, but nobody guarantees you, even with bad chances, you won't get 2 nuggets right after one another.
I didn't encounter a single nugget in my past week< farming quest, so i'm comfortable saying the odds are 1/500.
I took a paper and a pen and i made a record with 240 samples. This is the result:
1x earth sphere
4x intel crystals
7x mithril dragons
112 x 3 iron ores
2x water dragon Tablets
3x combos (Lava strike)&(Inferno)&(Fatal attack)
1x nugget
2x ice rocks
I updated some of the chances so they reflect the average of our values.
I will make more records and update the result above.
Mark my words, I will be last on the scoreboard one day.