For this case we have:
1st step:
We look for 30% of 400 by a rule of three of the form:
400 -------> 100%
x -----------> 30%
Where x is given by the number that represents 30% of 400.
We have:

2nd step:
We search for 20% of the number found, that is,
, using a rule of three:
120 -------> 100%
y -----------> 20%
Where y is given by the number that represents 20% of 120.
We have:

So, the number that Anthony found is 24.
3rd step:
According to the statement, we must find the% that represents the number of Anthony, based on the number 45. Through a rule of three we have:
45 -------> 100%
24 -----------> z%
Where z is given by the% that represents Anthony's number, knowing that 45 represents 100%.
We have:
%
Answer:
The number of Anthony represents 53.33% of 45.