Suppose that in a certain population of married couples, 30% of the husbands smoke, 20% of the wives
smoke, and in 8% of the couples both the husband and the wife smoke.
The question is:
For a randomly chosen couple, the husband does not smoke. What is the probability that the
wife also does not smoke?

^For this, I need to find the percentage of couples where neither the husband nor the wife smokes. Could somebody show me how to go about doing that?
Thanks!

Question

Suppose that in a certain population of married couples, 30% of the husbands smoke, 20% of the wives
smoke, and in 8% of the couples both the husband and the wife smoke.
The question is:
For a randomly chosen couple, the husband does not smoke. What is the probability that the
wife also does not smoke?

^For this, I need to find the percentage of couples where neither the husband nor the wife smokes. Could somebody show me how to go about doing that?
Thanks!

vocaloid · Answer

venn diagram should be useful here|dw:1443322112659:dw|

vocaloid · Answer

H only + 0.08 = 0.30
W only + 0.08 = 0.20

H only + W only + 0.08 + Neither = 1

solve for "Neither"

wondermath · Answer

Thank you!! I got it :)

vocaloid · Answer

ok, do you know how to  finish up the rest of the problem?