If the sum of n terms of the series 4+7+10+... is 209, find n
did that two hours ago:
http://www.jiskha.com/display.cgi?id=1460822853
To find the value of n, which represents the number of terms in the series, we need to understand the pattern of the series.
The given series is 4, 7, 10, ...
We can observe that each term is obtained by adding 3 to the previous term. This is an arithmetic series with a common difference of 3.
Using this information, we can write the formula to find the sum of the first n terms of an arithmetic series:
Sn = (n/2)(2a + (n-1)d)
Where:
Sn = sum of the first n terms
n = number of terms
a = first term
d = common difference
In this case:
a = 4 (first term)
d = 3 (common difference)
Substituting these values into the formula, we have:
209 = (n/2)(2(4) + (n-1)(3))
Now we can solve this equation to find the value of n.