Question

Donavan and Jones are randomly choosing chalices to drink from. 4 of the chalices contain purified water, 5 contain spoiled milk, and 6 contain diluted flat soda. Jones gets to choose a chalice from the remaining ones after Donavan drinks from 3 of them. If the chances of Jones choosing a chalice with purified water is then 1/3, how many of the chalices that Donavan drank out of contained purified water?

Answer 1

0

Explanation:

Chalice with purified water = 4

With spoiled milk = 5

With flat soda = 6

Probability of Jones drinking from a chalice with purified water after Donovan had drank from 3 = 1/3

Probability = required outcome / Total possible outcomes

Total possible outcomes = (4 + 5 + 6) = 15

After Donovan drinks 3 :

Total possible outcomes = (15 - 3) = 12

If the probability of Jones choosing a chalice with purified water is 1/3 then :

(Required outcome / Total possible outcomes) =1 /3

(Required outcome / 12) = 1 / 3

Required outcome * 3 = 12

Required outcome = 12 / 3

Required outcome = 4

Therefore, since initial number of chalice with purified water is 4,

4 - 4 = 0

Then Donovan did not drink from a chalice containing purified water.