On 11/08/19 3:06 AM, David Wright wrote:
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.
Agreed. I prefer to avoid multipliers with inverted dimension terms
like
that.
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.)
I wouldn't assume that; it's a common usage, even though I consider it
wrong :-) A bit like the American habit of saying "I could care less",
which also doesn't mean what they mean it to mean :-)
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.
Agreed. And many would consider it a 'legitimate idiom'. I personally
consider that from a linguistic and mathematical perspective, it
doesn't
make sense.
One hears stories of pedants insisting they be paid to carry goods out
of the shop because they were labelled "10x cheaper". No way Jos??.
I haven't actually insisted on that, but I've certainly thought it :-)
Similarly, one of our local fuel stations has (or had) vouchers that
say
things like '10c per litre off every litre of fuel' - which also
quickly
gets into trouble if taken literally :-)
Richard