Question

How to convert decimal form into p/q
form?

Answer 1

like 0.3 is decimal no.
then , write
0.3/1
and
3/10

Answer 2

Any decimal number can be represented as a number with denominator a power of 10 (10, 100, 1000 etc,)
Example
0.5 = 5/10
0.05 = 5/100
0.005 = 5/1000
I hope you got the pattern. If the decimal point is to the LEFT of the number, then you divide by a power of ten. And, the number of zeroes in the power of ten is determined by the number of digits the decimal point is placed before the number.
Example,
0.005
Decimal point is before the number, therefore divide by power of ten.
Decimal point is 3 digits before the number. Therefore divide by 1000 (3 zeroes).
Hence, by this method, you can convert any decimal to a fraction (p/q).