Rational numbers are numbers that can be written as a ratio or a fraction.
Irrational numbers are the opposite of rational numbers, it can't be written as a fraction; instead, it is written as a decimal number.
1) square root of 40 over 10 end root.
√ 40/10 ⇒ √4 ⇒ 2 ⇔ rational number. 2 can be written as 2/1, a fraction.
2) 8 pi
8 is a rational number while pi is an irrational number.
8 * 3.14159265359 = 25.1327412287 ⇔ irrational
3) 1/6 ⇔ rational
4) I don't understand the data given.