Question

A video game has been developed whereby the player must earn a certain number of experience points before progressing to the next level.
On level 1, a player must earn 1 experience point.
On level 2, a player must earn 7 experience points.
On level 3, a player must earn 15 experience points.
On level 4, a player must earn 25 experience points.
How many experience points must a player earn on level 7?

Answer 1

So,

All we have to do is look for patterns.

The levels go up by ones.  However, we have to figure out a pattern for the following set of numbers:
1, 7, 15, 25

Notice:
1 + 6 = 7
7 + 8 = 15
15 + 10 = 25

The amount of XP added to the requirement goes up by 2 more than the previous XP requirement.

Therefore, Level 5 will need 25 + 12 = 37 XP.

Level 6 will need 37 + 14 = 51 XP.

Finally, Level 7 will require 51 + 16 = 67 XP.

Answer 2

Level 5 = 37
Level 6 = 51
Level 7 = 67