Question

What is the value of the shown image?

Answer 1

Answer:

Option B

Step-by-step explanation:

To solve the problem you must develop the sum shown.

Note that the sum goes from i = 1 to i = 3.

Therefore they ask you to make the following sum

$4(0.5) ^ {1-1} + 4(0.5) ^ {2-1} + 4(0.5) ^ {3-1}$

Simplifying, we have:

$4(0.5) 0 + 4(0.5) 1 + 4(0.5)^ 2\\\\4(1) + 4(0.5) + 4(0.25)\\\\4 + 2 + 1 = 7$.

The answer is option B

Answer 2

Answer:

Option B. 7 is the correct answer.

Step-by-step explanation:

The given expression is $\sum_{t=1}^{3}[{4\times (\frac{1}{2})^{t-1}}]$

Now by putting the the values of t = 1, 2, 3 we get the sequence.

Then we can add the terms of the sequence

First term = $4.(\frac{1}{2})^{1-1} = 4.1 = 4$

Second term = $4.(\frac{1}{2})^{2-1}=4.(\frac{1}{2}) = 2$

Third term = $4.(\frac{1}{2})^{3-1}=4.(\frac{1}{2})^{2}=4.\frac{1}{4}=1$

So the total of these terms will be = 4 + 2 + 1 = 7

Answer is 7.