On Sat 10 Aug 2019 at 21:19:31 (+1200), Richard Hector wrote: > On 10/08/19 9:10 PM, deloptes wrote: > > Richard Hector wrote: > > > >> <rant> > >> Sorry, this usage grates with me. > >> > >> $amount cheaper that $price means subtract $amount from $price > >> > >> $x times $price means multiply $price by $x > >> > >> so "2 times cheaper (than $450)" is: > >> > >> $450 - (2 x $450) = -$450. > > > > so what multiplied by 2 gives 450? > > > > 450 is 100% or 1 > > 225 is 50% or 1/2 > > Right, so 225 is 50% cheaper, or half cheaper. Not twice cheaper. > > > perhaps this is the confusion, cause we are using daily language to refer to > > maths. > > Daily language is the problem, yes. I'm not saying my fight is an easy > one :-) > > > In fact I would do it the other way around. > > > > initial price x > > 1xtime x+(1*x) > > 2xtimes x+(2*x) > > > > this gives x=150 > > 450 is two times more expensive than 150 (or 200% more than), or three > times as expensive as 150 (or 300% as expensive). > 300 is two times as expensive as 150, or 100% more expensive than 150 > > We know that these don't work symmetrically; if you have a 50% discount, > you can't get the original price back by adding 50%, because it's 50% of > a different number.
"Expensive" is a dimensional term, like length and time. "Cheap" is in a different category, like shortness. A 6-inch nail is twice as long as a 3-inch nail, but one doesn't say the latter is twice as short. But if someone asked for a nail twice as short as this (holding up a 6-inch nail), you might assume they were a non-native speaker of English, or you might notice you're almost twice as tall as they are: ie it's a child. (And it would be polite to offer them a 3-inch nail. Learning all the categories takes time, and some people might have slightly different boundaries.) It's pretty obvious that Reco's meaning for cheapness was meant to be understood as a reciprocal cost and not as a discount. It might be a legitimate idiom in some parts; who knows. One hears stories of pedants insisting they be paid to carry goods out of the shop because they were labelled "10x cheaper". No way José. Cheers, David.
