# If 60 is equal to LX------

My nephew many times asks silly questions. Here is one.

If 60 = LX

Then 80 = X
Why?

Can it be?

• Are these algebraic symbols or Roman numerals? – Phylyp Jan 10 '18 at 14:44
• Just to save time for anybody thinking "Roman numerals" that doesn't remember what those would be; 60 is LX and 80 is LXXX. – user41531 Jan 10 '18 at 14:48
• Is it just me or would the lateral thinking tag feel at home here? – Brent Hackers Jan 10 '18 at 15:23
• Good suggestion. Will do it – DrD Jan 10 '18 at 16:59
• How old is your nephew? Just to help calibrate the silliness level. :) – Trevor Powell Jan 14 '18 at 5:55

I think

60 = "sixty" = "six t" = 6 * 10 = LX in Roman numerals

so

80 = "eighty" = "a t" = 1 * 10 = X in Roman numerals

Maybe?

If you assume the same rules as roman numerals but redefine the values, so that X=80 and L=20, both statements will be true.

Seems a bit overbroad, maybe the correct answer will fix that. In the meantime, here are a couple of the other kind.

perfectly fine maths, if L equals 0.75.

or

looking upside down, it kinda looks like XI = 09, from which it would be sensible to deduce that X = 08

• Not a Mathematics tag though Bass – DrD Jan 10 '18 at 14:50
• And X does not equal 8, it equals 10. – DonielF Jan 11 '18 at 0:24

Maybe..

You need 4 line strokes to write LX, that means you got a score of 100 - 4 * 10 = 60.
Hence, because X only needs 2 line strokes, you will get 100 - 2 * 10 = 80.

Silly me.

Perhaps

X means there's a cross in the number, and LX means there's a lack of a cross in the number. In this case, 60, "lacks a cross", and 80 has a "cross" because of the number 8?