Option A: 
is the value of 
Explanation:
It is given that the first term is 
The common difference is 
We need to determine the sum of 25 terms.
The sum of terms of an arithmetic series can be determined using the formula, ![S_n=\frac{n[2a_1+(n-1)d]}{2}](https://tex.z-dn.net/?f=S_n%3D%5Cfrac%7Bn%5B2a_1%2B%28n-1%29d%5D%7D%7B2%7D)
Substituting 
, and
Thus, we have,
![S_{25}=\frac{25[2(20)+(25-1)(-10)]}{2}](https://tex.z-dn.net/?f=S_%7B25%7D%3D%5Cfrac%7B25%5B2%2820%29%2B%2825-1%29%28-10%29%5D%7D%7B2%7D)
Simplifying the values, we get,
![S_{25}=\frac{25[40+(24)(-10)]}{2}](https://tex.z-dn.net/?f=S_%7B25%7D%3D%5Cfrac%7B25%5B40%2B%2824%29%28-10%29%5D%7D%7B2%7D)
![S_{25}=\frac{25[40-240]}{2}](https://tex.z-dn.net/?f=S_%7B25%7D%3D%5Cfrac%7B25%5B40-240%5D%7D%7B2%7D)
Subtracting the terms within the bracket, we get,
![S_{25}=\frac{25[-200]}{2}](https://tex.z-dn.net/?f=S_%7B25%7D%3D%5Cfrac%7B25%5B-200%5D%7D%7B2%7D)
Multiplying the terms in the numerator, we have,
Dividing, we get,
Thus, the sum of the 25 terms is
Therefore, Option A is the correct answer.
Answer:
B
Step-by-step explanation:
B. y=x+3
1=-2+3
2=-1+3
3=0+3
4=1+3
You have to find the percentage of calculators that are defective. to do this you do 6/900. Which equals 0.006666, you convert it to a percent by moving the decimal point 2 to the right which is 0.6666%, then you round to the nearest tenth as instructed in the question and you get 0.6%
3 x 3 1/2. Well you know 1/2 times two is one and three times two is six and six plus one is seven and seven plus 3 1/2 is 10 1/2
9 years * 5% = 45%
300,000 * 45 = 13,500,000
13,500,000 / 100 = 135,000 people
300,000 + 135,000 = 435,000 people after 9 years
