Algebra
posted by Bobby .
I reduced a diagram on my computer using a scale factor of 8o%(i.e. the linear dimensions of the diagram were reduced so they became 80% of the original dimensions). What scale factor is required to return the diagram to original size?

say we had a line 10 cm long
after reduction it is 8 cm long
now to get back to ten:
10 = scale factor * 8
10/8 = 1.25
That is the trouble with the %^&* stock market :)
If you lose 20%
You need to gain 25% to get back where you were :)