Answer:
The probability that she gets all 7 questions correct is 0.0078.
Step-by-step explanation:
We are given that Karri takes a 7 question true-false test and guess on every question.
The above situation can be represented through binomial distribution;
where, n = number of samples (trials) taken = 7 question
r = number of success = all 7 questions correct
p = probability of success which in our question is probability that
question is correct, i.e. p = 50%
Let X = <u><em>Number of question that are correct</em></u>
So, X ~ Binom(n = 7, p = 0.50)
Now, the probability that she gets all 7 questions correct is given by = P(X = 7)
P(X = 7) =
=
= <u>0.0078</u>
For this problem, we use the Fundamental Counting Principle where it states that if an event has n possible outcome and another independent event has m outcomes then there will be nm total possible outcome. Therefore, there are 3x4x3 = 36 possible different lunch John can make.
Answer:
40/21
Step-by-step explanation:
-4/7+(-4/3)
common factor is 21
=21/7×-4-21/3×4
=3×-4-7×4 all divided by 21
=-12-28 all divided by 21
=40/21