[BarTopDancer]

Thanks Alex! So B would be

.80 x .20 = .16
.8 x .8 x .8 = .51

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New question:

636 students answered the survey.

0.47 said they consumed more alcohol then usual

636 x .47 = 299 students who consumed more alcohol than usual

337 students did not consume more alcohol than usual. This is 53%.

(0.47 + 0.53 = 1)

So, I think the caculation would be

.47 x .53 x .47 = .12