For how to find a percentage of a percentage of a number easily, you solve the percent question in two steps.
a) Multiple the numbers given in the percentage question
b) Place decimal point after counting percent symbol (%) in the question
Example1
What is 20% of 20% of 20?
Solution
Multiply 20 x20 x 20 = 8000
See percent symbol (%) has been used 2 times in percent question. It means [1/100] x [1/100]. That is one % symbol means 2 zero whereas, 2 % symbol means 4 zeros. These 4 zeros will determine position of decimal point. Now start counting from right of 8000 and place decimal point after 4th digit. The answer will be 0.8000 or 0.8
Example 2
Find 30% of 40% of 50
Solution
Multiply 30 x 40 x 50 = 60000
Now count the Percent symbol (%) in percent question. Their number is 2. It means 4 zeros. Thus start counting from right of 60000 and place decimal point after 4th digit. It will look like 6.0000. So answer is 6.