Which number produces a rational number when added to 0.25?

0.75 can be added to 0.25 to make it 1 i. e a rational number; and many more numbers can also be added

Rational numbers are those numbers that can be written as a fraction in form a/b where b ≠ 0.

So, 0.25 = 25/100 and simplify into 1/4.

Any rational number added to 0.25 gives a rational number.

For example: 1, 0.5, 0.75, 2.25 etc.