Question

Which one of the following is an irrational number?
(a)√16/25, (b)√5,(c)3/9,√196

Answer 1

Rational numbers are those numbers which can be written in the form r=p/q,
where r-real number
p,q -integer with q not equal to zero

Eg: 3/4 is a rational numbers because 3 & 4 are integers.
But √2 is irrational since it cannot be written in the form p/q.
The numbers which are not rational are irrational.

In the given problem, answer is
(b)√5 is irrational

all other numbers can be written in the form p/q.
√16/25=4/5
3/9
√196=16 =16/1