Question

find the 5th term of sequence 1,3,7,15​

Answer 1

Answer:

a=1, a2=3, a3=7, a4=15

common difference (d) =a2-a1

=3-1

2

a5=?

By using formula;

An=a+(n-1) d

=1+(5-1) 2

=1+4×2

=1+8

=9

therefore, 5th term is 9.

Answer 2

Given,

1,3,7,15​

To Find,

The 5th term of the sequence is =?

Solution,

We can solve the question as follows:

It is given that we have to find the 5th term of the sequence: 1, 3, 7, 15.

Considering the first two terms, the difference between them is:

$3 - 1 = 2$

Considering the second and the third term,

$7 - 3 = 4$

Considering the third and the fourth term,

$15 - 7 = 8$

Clearly, the nth term of the sequence is given as:

$nth\: term = (n - 1)^{th}\: term + 2^{n - 1}$

Therefore, the 5th term is:
$5th\: term = (5 - 1)^{th}\: term + 2^{5 - 1}$
              $= 4th\: term + 2^{4}$

              $=15 + 16$

              $= 31$

Hence, the 5th term of the sequence is 31.