Which of these numbers can be classified as both real and rational?

A. 5.858585858558
B. 63.4
C. The square root of 21
D. The square root of 36

Question

Which of these numbers can be classified as both real and rational?

A. 5.858585858558
B. 63.4
C. The square root of 21
D. The square root of 36

anonymous · Answer

A, B, and D are all rationa numbers, as they can all be expressed as a fraction, where numerastor and denominator are integers (where denominator is not 0).

anonymous · Answer

Which ones the real number too?

ranga · Answer

They are ALL real.  Three of them are real and rational.  One of them is real and irrational.

raden · Answer

if they are rational numbers, obvious they are as real number too.
(rational number is part of real number)

anonymous · Answer

OH which one is real and irrational?

anonymous · Answer

sqrt(21) is real and irrational

ranga · Answer

C. The square root of 21. 21 is not a perfect square and so its square root  is irrational.