What is the approximate value of ? Round your answer to the nearest hundredth. 1.25 3.00 3.75 4.25

Question

asked Jun 16, 2021 159k views

2 Answers

Qweruiop · Answer 1 · 2021-06-22T20:58:54+0000

Option C:

$\sum_(n=1)^(5) 3(0.2)^(n-1)=3.75$

Solution:

Given expression:

$\sum_(n=1)^(5) 3(0.2)^(n-1)$

Summation means sum of the numbers.

Put n = 1 to 5 and sum all the numbers.

$\sum_(n=1)^(5) 3(0.2)^(n-1)$

=3(0.2)^(1-1)+3(0.2)^(2-1)+3(0.2)^(3-1)+3(0.2)^(4-1)+3(0.2)^(5-1)

=3(0.2)^(0)+3(0.2)^(1)+3(0.2)^(2)+3(0.2)^(3)+3(0.2)^(4)

Using exponential rule:
a^0=1 , so that
0.2^0=1

=3(1)+0.6+0.12+0.024+0.0048

=3.7488

= 3.75

$\sum_(n=1)^(5) 3(0.2)^(n-1)=3.75$

Option C is the correct answer.

Hence approximate value of
$\sum_(n=1)^(5) 3(0.2)^(n-1)$ is 3.75.