Answer:
A
Step-by-step explanation:
Total is ALWAYS 100%.
It says that 78.2% DO STUDY. It means the REST (100-78.2) DO NOT STUDY.
What is 100 - 78.2 ? It is 21.8%
To get the answer in decimal, we divide by 100:
[tex]\frac{21.8}{100}=0.218[/tex]
Hence, A is the correct answer.