Find the sum,m, $\mathrm { s } _ { \mathbf { n } },$ , o f the sequence.
-Find the sum of the odd integers between 18 and 54.
A)684
B)720
C)648
D)612

Question

Quizplus · Accepted Answer

The odd integers between 18 and 54 are 19, 21, 23, ..., 53. This is an arithmetic sequence with the first term $a_1 = 19$, the last term $a_n = 53$, and a common difference $d = 2$. The number of terms $n$ can be found using the formula for the nth term of an arithmetic sequence: $a_n = a_1 + (n-1)d$. Solving for $n$ gives $n = 18$. The sum of an arithmetic sequence is given by $S_n = \frac{n}{2} (a_1 + a_n)$. Substituting the values gives $S_n = \frac{18}{2} (19 + 53) = 9 \times 72 = 648$.

Find the Sum,m sn,\mathrm { s } _ { \mathbf { n } },sn​,

Find the Sum,m $\mathrm { s } _ { \mathbf { n } },$