Yes, 1.25 is a rational number. A rational number is defined as any number that can be expressed as the quotient or fraction a/b of two integers, where a is the numerator and b (the denominator) is not zero.
In the case of 1.25, we can express it as a fraction by writing it as 125/100. Both 125 and 100 are integers, and since 100 is not zero, this confirms that 1.25 is indeed a rational number. Additionally, we can simplify the fraction 125/100 to 5/4, which further demonstrates its rationality.