### 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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