Question

Find the number of terms in the following arithmetic sequence.
1, 3, 5, 7, . . ., 51

Answer 1

Looks like a(n)=1+2(n-1),
n=1, a(1)=1
n=2, a(2)=3
so n=26, a(26)=1+2(26-1)=51
Therefore 26 terms in the sequence.

Answer 2

this is an example of an arithmetic progression, where every adjacent values have a common difference... the general formula is given by...
a(n) = a(1) + (n - 1) x d
where:
a(1) = the value of the 1st term,
a(n) = the value of the nth term,
n = the number of terms in the given sequence,
d = the common difference between adjacent values in a sequence....

Answer 3

from the solution of @DominicNg... you just plug-in the given values... and you can solve for n....