Not sure at all but i think the 18 one
The probability of event A and B to both occur is denoted as P(A ∩ B) = P(A) P(B|A). It is the probability that Event A occurs times the probability that Event B occurs, given that Event A has occurred.
So, to find the probability that you will be assigned a poem by Shakespeare and by Tennyson, let Event A = the event that a Shakespeare poem will be assigned to you; and let Event B = the event that the second poem that will be assigned to you will be by Tennyson.
At first, there are a total of 13 poems that would be randomly assigned in your class. There are 4 poems by Shakespeare, thus P(A) is 4/13.
After the first selection, there would be 13 poems left. Therefore, P(B|A) = 2/12
Based on the rule of multiplication,
P(A ∩ B) = P(A) P(B|A)P(A ∩ B) = 4/13 * 2/12
P(A ∩ B) = 8/156
P(A ∩ B) = 2/39
The probability that you will be assigned a poem by Shakespeare, then a poem by Tennyson is 2/39 or 5.13%.
Answer:
If Ted can clear a football field of debris in 3 hours, in one hour they will have cleared 1/3 of it.
If Jacob can clear a football field of debris in 2 hours, in one hour they will have cleared 1/2 of it.
So if they work together, they will clear 1/2 + 1/3, which is 5/6, in one hour.
So the equation we get is 5/6*x = 1 and if we divide both sides by 5/6 we get that x = 1.2 hours
