## Archive for February, 2015

## Problem 596

**Find the sum of the sequence you created in problem.Divide the sum by 11. What do you notice?**

**2, 3 ,5 8, 13, 21, 34, 55, 89, 144**

**Solution**

The sum of the Fibonacci sequence in problem = 374

Divide by 11 the sum = 374/11 = 34

We are notice the middle term of the number is remove.

## Problem 595

Find the 5^{th} term of the sequence in which t_{1} = 8 and t_{n} = -3t_{n-1.}

_{ }Solution:-

t1 = 8

t2 = -3(t1) = -3(8) =-24

r = -3

a5 =

a5 = 648

## Problem 594

Find the four geometric means between 4 and 972

**Solution:-**

4 = 972

= 243

r = 3

So the four geometric means are 12, 36, 108 and 324.

## Problem 593

What are the next three terms of the following sequence?

-2, 4, -8, 16

**Solution:-**

a1 = -2, and r = -2

an = a1*

So the next three terms -32, 64, -128

## Problem 592

What are the next three terms of the following sequence?

8, 40, 200, 1000

**Solution:-**

a1 = 8, and r = 5

an = a1*

So the next three terms 5000, 25000, 125000

## Problem 591

Find S_{20} for the series -1 + -3 + -5 + -7 +…

**Solution:-**

a1 = -1, d = -2

S_{20} = [2*a1 + (n-1)*d]

S_{20} = [2*(-1) + (20-1)*-2]

S_{20} = – 400

## Problem 590

Find S_{10} for the series 2 + 7 + 12 + 17 +…

**Solution:-**

a1 = 2, d = 5

S_{10} = [2*a1 + (n-1)*d]

S_{10} = [2*2 + (10-1)*5]

S_{10} = 245

## Problem 589

Find the 10th term of an arithmetic sequence if t_{1} = 2.1 and t_{4} = 1.83.

**Solution:-**

1.83 = 2.1+(4-1)d

d = -0.09

n10th = 2.1+(10-1)*(-0.09)

n10th = 1.29