Question

Find the sum of first term of the sequence 1,2,4,8,12

Answer 1

Answer:

The right solution is "18". A further explanation is given below.

Step-by-step explanation:

The given series is:

1,2,4,8,12

Here,

First term,

a₁ = 1

Second term,

a₂ = 2

Last term,

n = 12

Now,

The sum of the sequence will be:

⇒ $S_n = \frac{n ( a 1 + a 2 ) }{2}$

On substituting the values, we get

⇒      $=\frac{12(1+2)}{2}$

⇒      $=\frac{12\times 3}{2}$

⇒      $=\frac{36}{2}$

⇒      $=18$