The Xp System and the Rank System

At the beginning you are rank 6 and level 1
to Level up you have to complete 5 quests
To rank up you have to be level 10
At 5th Rank it takes 10 quests to level up
to Rank up to the 4th Rank you need to be level 20
At the 4th Rank you it takes 10 quests to level up
To Rank up to the 3rd Rank you need to be level 35
At the 3rd Rank it takes 15 quests to level up
To Rank up to the 2nd Rank you need to be Level 50
At the 2nd Rank it takes 15 quests to level up
To rank up to the 1st rank you need to be level 65
At the 1st rank it takes 20 quests to level up