Question

Write the Hindu-Arabic numbers of the following:

$\text{XXXIX}$

Answer 1

In the given question,

$$\begin{gathered} \text{X}=10 \\ \text{IX}=\left(10-1\right)=9 \end{gathered}$$

So,

$$\begin{gathered} \text{XXXIX}=\left[\left(10+10+10+\left(10-1\right)\right)\right] \\ =\left(10+10+10+9\right) \\ =39 \end{gathered}$$

Hence, the correct answer is $39$.