Concept:
Take the third number as the base.
Step 1: Assume the third number.
Let the third number be:
\[
100
\]
Then:
First number is \(20\%\) less:
\[
100-20=80
\]
Second number is \(30\%\) less:
\[
100-30=70
\]
Step 2: Find what percent second number is first number.
Required:
\[
\frac{\text{First}}{\text{Second}}\times 100
\]
\[
=\frac{80}{70}\times100
\]
\[
=\frac87\times100
\]
\[
=\frac{800}{7}
\]
\[
=114\frac27\%
\]
Thus, the required answer is:
\[
\boxed{114\frac27\%}
\]