How to simplify these fractions 0.25/0.75 and 6.25/12.5

One of the easier ways of simplifying 0.25/0.75 would be to recognice that 0.25 goes into 0.75 3 times.  Thus, 0.25/0.75 = 1/3.

Similary, 6.25/12.5 = 6.25/12.50 = 1/2.

You can always convert any decimal to a fraction by "using as many zeros in the denominator as there are decimals and lose the dot atop", let's do so with these, and then simplify them,