The first term of an A.P is 2 and its common difference is 3, find the sum of the first 11 terms of the A.P
the 11th term is ... 2 + (10 * 3) = 32
sum of 1st 11 terms ... (2 + 32) * (11 / 2)
To find the sum of the first 11 terms of an arithmetic progression (A.P.), we can use the formula:
Sn = (n/2) * [2a + (n-1)d],
where Sn is the sum of the first n terms, a is the first term of the A.P., d is the common difference, and n is the number of terms.
In this case, the first term (a) is 2 and the common difference (d) is 3. We need to find the sum of the first 11 terms (n = 11).
Substituting the given values into the formula, we have:
Sn = (11/2) * [2(2) + (11-1)(3)],
= (11/2) * [4 + 10(3)],
= (11/2) * [4 + 30],
= (11/2) * 34,
= (11 * 34) / 2,
= 374 / 2,
= 187.
Therefore, the sum of the first 11 terms of the A.P. is 187.