Answer:
190 chairs
Step-by-step explanation:
-This is an arithmetic progression with the first term a=10, the common difference is d=2 and the number of terms n=10.
-The sum of n terms in the progression can be calculated as follows:
![S_n=0.5n(a_1+a_n)](https://tex.z-dn.net/?f=S_n%3D0.5n%28a_1%2Ba_n%29)
Where
is the sum of the progression's terms.
are the first and last terms of the progression.
#We calculate
as below:
![a_n=a_1+d(n-1)\\\\a_{10}=10+2(10-1)\\\\=28](https://tex.z-dn.net/?f=a_n%3Da_1%2Bd%28n-1%29%5C%5C%5C%5Ca_%7B10%7D%3D10%2B2%2810-1%29%5C%5C%5C%5C%3D28)
#We then substitute to calculate the sum of the terms:
![S_n=0.5n(a_1+a_n)\\\\=0.5\times 10(10+28)\\\\=190](https://tex.z-dn.net/?f=S_n%3D0.5n%28a_1%2Ba_n%29%5C%5C%5C%5C%3D0.5%5Ctimes%2010%2810%2B28%29%5C%5C%5C%5C%3D190)
Hence, 190 chairs are needed for the 10 rows.
1 nickel = 5 cents
1 dollar = 20 nickels
You can make 13 dollars plus 16 nickels left over
20 * 13 = 260
then 260 + 16 = 276
Each successive term is 3 times the previous one, so you could write the sum as
Answer:
88
Step-by-step explanation:
We have 4 numbers that sum to 354.
So, let us use a letter to represent the first consecutive number in the sum.
Let it be x.
x + (x + 1) + (x + 2) + (x + 3) = 354
We want (x + 1), the second number in the sequence.
Simplify x + (x + 1) + (x + 2) + (x + 3) = 354
x + (x + 1) + (x + 2) + (x + 3) = 4x + 6 = 354
4x + 6 = 354
4x = 354 - 6
4x = 348
x = 348/4 = 87
so x + 1 = 87 + 1 = 88
The answer is D. -24 - 49i/13