Is 5 a Rational or Irrational Number?

To determine whether 3.5 is a rational or irrational number, we need to express it as a fraction. A rational number can be expressed as a ratio of two integers.

Given,

3.5 can be written as 3.5 = 7/2,

We can prove mathematically that 3.5 is a rational number.

Proof:

Let x = 3.5

Multiplying both sides by 2:

2x = 2 × 3.5

2x = 7

Dividing by 2:

x = 7/2

Since 3.5 can be expressed as the fraction 7/2, which is a ratio of two integers, we can conclude that 3.5 is a rational number.

OR

Express 3.5 as fraction : 3.5 = 35/10.

Dividing the numerator and denominator by their GCD i.e. 5 :

35 ÷ 5 / 10 ÷ 5 = 7/2

Therefore, 3.5 can be represented as: 3.5 = 7/2 which is ratio of two number where p = 7 , q = 2 ≠ 0.

So, We can say that 3.5 is a rational number.

3.5 a Rational Number. Before moving further it’s important to understand the definitions of rational and irrational numbers.