After surveying 995 adults, 81.5% of whom were over 30, the National Sleep Foundation reported that 36.8%

Question:

After surveying 995 adults, 81.5% of whom were over 30, the National Sleep Foundation reported that 36.8% of all the adults snored. 32% of the respondents were snorers over the age of 30.
a) What percent of the respondents were 30 or less and did not snore?
b) Is snoring independent of age? Explain.