The probability that an event will happen and the probability that the even will not heppen-
A.has a sum of 1
B.have a quotient of 1
C.have a product of 1
D.have a difference of 0
2007-02-11 03:56:48 · 7 answers · asked by Roman H 1 in Science & Mathematics ➔ Mathematics
It's A
Whenever you total all probabilities, you will get 1.
For example,
You have 1 coin. You can either get heads or tails.
P(heads) = 1/2
P(tails) = 1/2
The probability of getting heads or tails is:
P(heads) + P(tails) = 1
Another way to look at it is:
P(tails) = P(not heads)
As said, P(heads) + P(not heads) = 1
This will always be true.
Let x be an event.
P(x) + P(not x) = 1
2007-02-11 04:11:40 · answer #1 · answered by Anonymous · 0⤊ 0⤋
The answer is A. An event happens with a probability p or not happen with a probability of (1-p), so the sum is 1.
See it this other way. Event happen or event not happen, this complete event is always true, so its probability is 1.
2007-02-11 12:07:37 · answer #2 · answered by Jano 5 · 1⤊ 0⤋
A. The probability that an event will happen is, say 30% or 0.3. The probability that it won't happen is 70% or 0.7. Therefore the sum is 1. This is always the case (and is convention).
2007-02-11 12:03:04 · answer #3 · answered by the_emrod 7 · 0⤊ 0⤋
has a sum of 1. Because if something is going to happen it's probablility needs to be bigger than 1 and if something is not going to happen at all then it would be 0. And 1+0=1
2007-02-11 12:01:16 · answer #4 · answered by glamorous 2 · 0⤊ 0⤋
A.
Always.
By definition.
It's possible to write other questions that look like they have the same answer and actually don't, but this one is the real deal.
B-D make no sense.
2007-02-11 12:11:12 · answer #5 · answered by Curt Monash 7 · 0⤊ 0⤋
It really depends on the event. But your teacher wants A as the answer.
2007-02-11 12:05:41 · answer #6 · answered by Anonymous · 0⤊ 1⤋
i think its B
2007-02-11 11:59:58 · answer #7 · answered by Julie 3 · 0⤊ 1⤋