20 ribbons
Explanation:
1st day— 5 ribbons
2nd day—2 x 5 = 10 ribbbns
3rd day— 2 x 10 = 20
Hope this helps
Answer:
He needs $1.64 he has to pay $26.64
Step-by-step explanation:
$25 is what Edwin has
5.95 x 2 = $11.19
$2.50 x 3 = $7.50
11.19 + 7.50 + 7.95 = $26.64
Given:
First term of an arithmetic sequence is 2.
Sum of first 15 terms = 292.5
To find:
The common difference.
Solution:
We have,
First term: 
Sum of first 15 terms: 
The formula of sum of first n terms of an AP is
![S_n=\dfrac{n}{2}[2a+(n-1)d]](https://tex.z-dn.net/?f=S_n%3D%5Cdfrac%7Bn%7D%7B2%7D%5B2a%2B%28n-1%29d%5D)
Where, a is first term and d is common difference.
Putting
, n=15 and a=2 in the above formula, we get
![292.5=\dfrac{15}{2}[2(2)+(15-1)d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B2%282%29%2B%2815-1%29d%5D)
![292.5=\dfrac{15}{2}[4+14d]](https://tex.z-dn.net/?f=292.5%3D%5Cdfrac%7B15%7D%7B2%7D%5B4%2B14d%5D)
![292.5=15[2+7d]](https://tex.z-dn.net/?f=292.5%3D15%5B2%2B7d%5D)
Divide both sides by 15.




Dividing both sides by 7, we get


Therefore, the common difference is 2.5.
Answer:
Isnt it where you write it in the easiest way to understand it? sorry if its wrong :/
Step-by-step explanation:
Answer:
B.
Step-by-step explanation: