Here's a fairly simple riddle: When is 90 greater than 100? (And it's not when you're on the negative side of the number line. Although it is true, it is not the answer)
Some joke answers here and some more serious ones too.
Rotate 180 degrees, 06 is larger than 001
In roman numerals, XC has more letters than C
The sum of digits is larger for 90.
90 (in decimal) is greater than 100 (in binary).
The most common answer: Enter 90 in a microwave, is 90 seconds while entering 100, is 1 minute or 60 seconds
Heres an original answer: In an isoceles triangle, the largest area is when one of the angles is a right angle. So an isoceles triangle with 100 degree angle is lesser than one with a 90 degree angle.
Heres an original answer, part 2: The colour #000090 (dark blue) is brighter (greater in luminosity) than #000100 (very dark green)
From a programmer's perspective:
In lexicographical order. In Python:
90 > 100→
False. But compare as strings, and you get
"90" > "100"→
In lexicographical order, like in a dictionary, you compare characters sequentially. So to check whether
"def" > "abc", you first check whether
"d" > "a"(which it is, because it's later in the alphabet). Because it is, you don't have to check the rest of the string. The same holds when you treat numbers as characters. To check
"90" > "100", first check whether
"9" > "0"(which it is, because it's a larger number/later in ASCII). So you immediately conclude
More joke/serious answers.
90 isn't larger than 100, but it is greater than 100. Just look at it. Those smooth prime factors. So great.
In base 8, '90' isn't well-defined, but morally it's larger than 100.
class Fixnum; def >=(other) true end end; print 90 >= 100 # prints "true"