Which number is a irrational number?

a. 15

b. 1.15

c. 25

d. 1.25 as a repeated decimal

none.

Step-by-step explanation:

An Irrational Number is a real number that cannot be written as a simple fraction.

So, checking one by one

a and c) 15 can 25 are not an irrational number because they are an integer and all integers are rational numbers. and can be written as 15/1 or 25/1

b) 1.15 is not an irrational number its fraction form is 23/20

d) Repeating decimals are considered rational numbers because they can be represented as a ratio of two integers. If a number is terminating or repeating, it must be rational.