Why mod = 0.25?

Question

https://code.sololearn.com/c9VFw5re3xXh/?ref=app

Answer 1

Because 1.25 / 0.5 yields 2 (quotient) with 0.25 as the remainder.
1.25 / 0.5 = 2 (quotient)
1.25 - (0.5 * <quotient>) = 0.25 (remainder)