Question

Which number produces an irrational number when added to 0.4?

Answer 1

Any number that is irrational, such as
0.4 + pi because pi is an irrational number.

Answer 2

Answer with explanation:

Irrational number: A number is said to be irrational ,if decimal expansion of that number is non terminating and non repeating.For example: √2,∛3,π,√7 are all Irrational.

⇒When any rational number is added to , an irrational number ,it gives irrational number.That is sum of, Irrational and Rational is Irrational.

For example, 4 +√3, 5 + π, 4 - √2, all are Irrational.

→→So,when ,0.4 is added to ,√2,√3,π...any irrational number,that is

  0.4 + √2, 0.4 +√3, 0.4 + π

Any of these irrationals, it will produce an Irrational number.