Can someone explain this to me?

Question

solomonzelman · Answer

What is the percentage decrease from 17 to -8.

solomonzelman · Answer

68?

anonymous · Answer

well it changes 25 places on the number line. from 17. it would have to be -100%+something. I cant remember how to set these up though

solomonzelman · Answer

$$17~\div~25~\times~100~~~=~~68%$$I would think so, right?

anonymous · Answer

hm. if we increase 17 by 68 percent though it wouldn't move it in the positive direction 25 places. 100% would be 17 places

solomonzelman · Answer

yes, that what makes no sense to me? how can 25 be 68% and 17 be 100%?
how can be 68% be more than 100%

anonymous · Answer

-147% I think found this formula here http://math.about.com/od/percent/a/alg1perc.htm take the (older - the new)/older so (17-(-8)/17

solomonzelman · Answer

-147% ?! WOW, OMG

solomonzelman · Answer

I see what you are showing, but isn't that really really weird?

solomonzelman · Answer

a 147 % decrease is 25 and 100% is 17....

anonymous · Answer

well we know it has to be more than 100 percent because if you take 100 percent from 17 its 0

solomonzelman · Answer

I see what you did, but it just looks abstruse although I understand that it really should be like this....

anonymous · Answer

ya, its a little weird. sometimes in math I just learn to accept certain things, the same in physics.

solomonzelman · Answer

Okay, thank you, got it!