All categories

3 years ago

Find the sum of the first 20 terms of the arithmetic sequence 4, 10, 16, 22....

Mathematics

1 answer:

hammer [34]3 years ago

3 0

n = 20

d = 6

a = 4

L = a + (n - 1)*d

L = 4 + (20 - 1)*6

L = 4 + 19*6

L = 118

Sum = (a + L)*n/2

Sum = (4 + 118) * 20/2

Sum = 122 * 10

Sum = 1220

You might be interested in

The total simple interest on $1600 invested for five years is $224. What is the percentage rate per annum?

mash [69]

Answer:

The percentage rate per annum is 2.8%

Step-by-step explanation:

We need to multiply the principal by the time, then divide the interest by the product of P×T, so:

1,600 × 5 = 8,000

224 ÷ 8,000 = 0.028

Then we convert our final product to a percentage.

0.028 to a percent is 2.8%

6 0

2 years ago

Read 2 more answers

Please help.<br> Its a True or False question.

faust18 [17]

Answer:

1. False

2. True

3. True

Step-by-step explanation:

Remark

The point of this question is to encourage you to make use of your calculator. Every calculator can find square roots as far as I know.

Givens

$\sqrt{70}$ = 8.367

$\sqrt{72}$ = 8.49

$\sqrt{77}$ = 8.77

One

Point A is roughly 8.15. The square root of 70 is over 8.3 So square root 70 is to the right of point A. False.

Two

Square root 72 is 8.49. B is 8.3 and C is 8.6. The statement is True

Three

sqrt(77) = 8.77. Point D is 8.75. The answer is true, but I wouldn't want to bet money on it. The difference is slightly less than 2 100s.

4 0

2 years ago

Read 2 more answers

Find parametric equations for the line through the point (0, 2, 2) that is parallel to the plane x + y + z = 4 and perpendicular

Oxana [17]

Answer: X = 3t, Y =2 - t, Z =2

Step-by-step explanation: the plane

x + y + z =4has normal vector

M =<1,1,1> and the line

x = 1 + t, y = 2 − t, z = 2t has direction

v =<1, −1, 2>. So the vector

A= n × v

=<1, 1, 1> × <1, −1, 2>

=<2−(−1),1−2,−1−1>

=<3,−1,−2>

5 0

3 years ago

A book had a lenght of 5 inches and a width of 10 inches. What is the area of the book

babunello [35]

Answer:

Step-by-step explanation:

7 0

3 years ago

A store manager paid $95 for an item and set the selling price at $116.85. What was the percent markup?

Neporo4naja [7]

We have been given that a store manager paid $95 for an item and set the selling price at $116.85. We are asked to find the percent mark-up.

We will use percent increase formula to solve our given problem.

$\text{Percent increase}=\frac{\text{Final}-\text{Initial}}{\text{Initial}}\times 100\%$

$\text{Percent increase}=\frac{\$116.85-\$95}{\$95}\times 100\%$

$\text{Percent increase}=\frac{\$21.85}{\$95}\times 100\%$

$\text{Percent increase}=0.23\times 100\%$

$\text{Percent increase}=23\%$

Therefore, the mark-up will be 23% and option 'b' is the correct choice.

6 0

2 years ago