The number 21 is an irrational number if 21 canNOT be expressed as a ratio, as in irRATIOnal.
A quotient is the result you get when you divide one number by another number. For 21 to be an irrational number, the quotient of two integers canNOT equal 21.
In other words, for 21 to be an irrational number, 21 canNOT be expressed as a ratio where both the numerator and denominator are integers (whole numbers).
The number 21 can be expressed as 21/1 where 21 is the numerator and 1 is denominator.
Thus, the answer to the question "Is 21 an irrational number?" is NO.
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Is 22 an Irrational Number?
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