Question

What is the answer for this problem and please explain?

Answer 1

As given by the question

There are given that the sequence:

`64.5,\text{ 65, 65.5, 66, 66.5,}\ldots`

Now,

From the formula of the nth term of the arithmetic sequence:

`a_n=a_1+(n-1)d`

Where,

`\begin{gathered} a_1=65, \\ d=a_2-a_1 \\ d=65.5_{}-65 \\ d=0.5 \end{gathered}`

Then,

Put all the terms into the above formula:

So,

`A=0.5n\ldots\text{.}(1)`

Now,

If the first term is 65

Then,

`65-0.5=64.5`

Then,

Add the above value into equation (1)

So,

`A=0.5n+64.5`

Hence, the correct option is C.