Greetings from Brasil...
First let's define the rational number....
→ Division between two numbers with the detail that the dividend or denominator cannot be zero
A/B or A ÷ B
where B ≠ 0
(just for the sake of knowledge. If B = 0 we would have +∞ as an answer)
A ∈ ℤ
and
B ∈ ℤ* (B ≠ 0)
In this way, when dividing A by B, we will obtain a whole number or a number with a decimal (finite decimal or periodic tenth)
Let's go to the alternatives
A = 4/5 = 0,8 (finite decimal)
4 ∈ ℤ and 5 ∈ ℤ*, so we have a rational number
B = √27 = 5.1961524227066318805823390245176
(There is no repetition of tithing periods (numbers after the point) - non-periodic tithe). So we have an Irrational Number
C = 4.020020002000002
There is no periodic tenth - Irrational Number
D = √31 = 5.5677643628300219221194712989185
Irrational Number - Non-periodic tithe
