Non-terminating and non-repeating decimals are irrational.
If the denominator of a rational number is in the form of where n and m are non-negative integers, then the rational number is terminating.
0.2 = 2/ 10 = 2/ (2 x 5)
∴ 0.2 has terminating decimal and is a rational number.
3.1415926535… is non-terminating and non-repeating.
∴ 3.1415926535… is irrational.
1/0.2 = 10/2
∴ 1/ 0.2 has terminating decimal and is a rational number.