when a number is decreased by 20% and the result is 112, what was the origional number

Call the number "N"   ... and if it decreased by 20%, it must just be 80% of what it was = 112

So  ...  80% of N = 112      ..  or....  in equation form

.80*N = 112          divide both sides by .80

N = 112/.80 = 140