Answer :
We know rational number can be expressed as , Where q 0 and p and q are integers . Or have decimal digits terminating or non terminating but repeating .
SO,
We assume our Two rational number :
A = , Here b 0 and a and b are integers .
And
B = , Here d 0 and c and d are integers .
So,
A B = =
And
Integers Integers = Integers , So
ab and cd also integers , So
A B also a rational number .
So,
We can say multiple of rational number also a rational number . ( Hence Proved )