Question

Express 3.425 in the form of p/q where 25 is repeated

Answer 1

Let the given number be x
x = 3.4252525..                        -- Equation 1
As the periodicity ( the number of digits repeated ) of the given number is 2,
Multiply the number with 10 raised to the power of 2 or 100
Then you get,
100x = 342.52525..                  -- Equation 2
Now solve both the equations
Equation 2 - Equation 1
                    100x = 342.52525..
                  -       x =     3.42525..
                 --------------------------------
                       99x = 339.1
                          x = 339.1/99
                          x = 3391/990