Answer:
140
Step-by-step explanation:
The arithmetic series is 5, 7, 9, 11, ........., 23.
First u have to determine the no. of terms that can be done by using
Tₙ = [a + (n - 1)d]
Tₙ-------nth term
a---------first term
n---------no.of terms in the series
d---------common difference
here a = 5,d = 2.
let it contain n terms Tₙ= [a + (n-1)d]
Substitute Tₙ, a, and d in the equation
23 = 5 + (n - 1)2
Subtract 5 from each side.
18 = (n-1)2
Divide each side by 2
(n - 1) = 9
Add 1 to each side
n = 9 + 1 = 10
The sum of the arithmetic sequence formula: Sₙ= (n/2)[2a+(n-1)d]
Substitute Sₙ, a, n and d in the equation
Sₙ= (10/2)[2(5) + (10-1)2]
Sₙ= (5)[10 + (9)2]
Sₙ= 5[10 + 18]
Sₙ= 5[28] = 140
Therefore the sum of the arithmetic sequence is 140.
For the given situation we have a total of 259,459,200 permutations.
<h3>
How many permutations are?</h3>
First, how we know that it is a permutation?
Because the order matters, we aren't only selecting 8 out of the 15 people, but these 8 selected also have an order (is not the same thing to finish the race first than fourth, for example).
Then we need to find the number of permutations, to do it, we need to find the numbers of options for each of the 8 positions.
- For the first position there are 15 options.
- For the second position ther are 14 options (one runner already finished).
- For the third position there are 13 options.
- And so on.
Then the total number of permutations (product between the numbers of options) is:
P = 15*14*13*12*11*10*9*8 = 259,459,200
If you want to learn more about permutations:
brainly.com/question/11732255
#SPJ1
Answer:4
Step-by-step explanation:
P(2)
(2)
4
−3(2)
2
+k(2)−2
16−3⋅4+2k−2
2+2k
2k
k
=10
=10
=10
=10
=8
=4
