Multiply the triangles then divide to find the missing number
Using the arrangements formula, it is found that there are 24 ways for them to stand in line so that the youngest person is always first, and the oldest person is always last.
<h3>What is the arrangements formula?</h3>
The number of possible arrangements of n elements is given by the factorial of n, that is:

In this problem, we have that there are 6 people. The youngest person(Leslie) has to be first, while the oldest(Parvinis) has to be last, while the remaining 4 can be arranged, hence the number of ways for them to stand in line is given by:

More can be learned about the arrangements formula at brainly.com/question/24648661
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Sinx=1/2
sin30=1/2
therefore x=30 degree
Answer:
you want 4 correct and 16 incorrect
there are 20 questions
each question has four answers, so
P(right answer) = 1/4
P(wrong answer) = 3/4
----
Since you want 4 correct of 20 we have a combination of 20C4
This is a binomial problem where p = 1/4, q = 3/4 and we get
(20 "choose" 4)*(probability correct)^(number correct)*(probability incorrect)^(number incorrect)
putting numbers in we get
(20c4)*(1/4)^4*(3/4)^16
This gives us
~ .189685
Step-by-step explanation: