You play your Xbox 360 every day for a month. Each week you realize that every time you play, your battery lift goes down by 5% each week. Say you don’t play for two weeks, how much %___ are you saving a week by not playing.

Question

You play your Xbox 360 every day for a month. Each week you realize that every time you play, your battery lift goes down by 5% each week.  Say you don’t play for two weeks, how much %___ are you saving a week by not playing.

Damon · Answer

If you save 5% the first week you are down to 95%
If you then save 5% of that the second week you are down to 95% of 95% = .9025 or at 90.25% of full charge which means you saved (1/2)(1-.9025)(100) = 4.875% per week on the average. That is hardly fourth grade. It is more in the compound interest regime of math.