Brain Teasers
Correct Equation?
2 x 10 = 2 x 11
This is a correct statement, because 2 x 10 (in base 10) equals 2 x 11 (in base 9).
Generalized: N>=3; 2 x 10 (in base N) = 2 x 11 (in base N-1).
Can you find another way to justify that this equation is actually correct?
This is a correct statement, because 2 x 10 (in base 10) equals 2 x 11 (in base 9).
Generalized: N>=3; 2 x 10 (in base N) = 2 x 11 (in base N-1).
Can you find another way to justify that this equation is actually correct?
Hint
Remember it is in the trick category, not math.Answer
Twice ten is twenty, twice eleven is twenty too (two).Hide Hint Show Hint Hide Answer Show Answer
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Comments
I didn't really like it... Looks like it should be in the math section.
What???? I liked it, and it is clearly a trick not math!! The trick is it looks like math!
It was a perfect trick! (I was lost by the second line, but the answer made sense so I liked it.)
Lol! I got it because my math teacher said this as a joke, but I loved the way you through people off with the complicated math bit at the start!
You really through me off with this one, but that's what made it good!
cute answer, although it would be better if it were spoken
here is another 3*10=16*2
and another 4*10=6*7
and another 4*10=6*7
that is cute
heheh - very cute
sounds a lot like a joke though (like the old, what time is it when you need to go to the dentist? joke)
sounds a lot like a joke though (like the old, what time is it when you need to go to the dentist? joke)
one of the best teasers on the site definately going to my favorites
Huh?
Huh?
also if you think of x as a varible that equals zero...
Great teaser!
Wow, that's fantastic!
that was so cool
it's more of word play...
good one
I knew it. This is a good teaser by the way.
This has nore to do with math than anything else
ANOTHER SOLUTION IF WE WRITE IN ROMAN NUMERALS lxx=lxll both have same no of match sticks or straight lines
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