What is the sum of the first twelve term of an A.P whose 1st term is 15 and the common difference is 13
Recall that for an AP,
Sn = n/2 (2a + (n-1)d)
so plug and chug
Jane
Answers to my question
To find the sum of the first twelve terms of an arithmetic progression (A.P.), we can use the formula for the sum of n terms of an A.P., which is given by:
Sn = (n/2) * (2a + (n - 1)d)
where Sn is the sum of the first n terms, a is the first term, d is the common difference, and n is the number of terms.
Given that the first term (a) is 15, the common difference (d) is 13, and the number of terms (n) is 12, we can substitute these values into the formula and calculate the sum (Sn).
Sn = (12/2) * (2 * 15 + (12 - 1) * 13)
= 6 * (30 + 11 * 13)
= 6 * (30 + 143)
= 6 * 173
= 1,038
Therefore, the sum of the first twelve terms of the arithmetic progression is 1,038.