6.6 Arithmetic Series
Chapter
Chapter 6
Section
6.6
Solutions 24 Videos

Determine the sum of each arithmetic series.

• a=4, t_n=9, n=6

• a=10, d=-2, n=12

• a=7, t_n=-22, n=12

1.37mins
Q1abc

Determine the sum of each arithmetic series.

• a=-4, t_n=17, n=20

• \displaystyle{a=\frac{1}{3}}, \displaystyle{-\frac{1}{2}}, n=7

• a=3x, t_n=21x, n=15

1.42mins
Q1def

For each arithmetic series, state the values of a and d. Then, determine the sum of the first 20 terms.

• 5+9+13+...

• 20+25+30+...

• 45+39+33+...

2.12mins
Q2abc

For each arithmetic series, state the values of a and d. Then, determine the sum of the first 20 terms.

• 2+2.2+2.4+...

• \displaystyle{\frac{1}{2}+\frac{3}{4}+1+...}

• -5-6-7-...

1.43mins
Q2def

The first and last terms in each arithmetic series are given. Determine the sum of the series.

• \displaystyle{a=\frac{1}{2}}, t_8=4

• a=19, t_{12}=151

• a=-5, t_{45}=17

• a=11, t_{20}=101

1.55mins
Q3

Determine the sum of each arithmetic series.

(a) 6+13+20+...+69

(b) 4+15+26+...+213

(c) 5-8-21-...-190

(d) 100+90+80+...-100

4.21mins
Q4

Determine the sum of each arithmetic series.

• -1+2+5+...+164

• 2-5-12-...-222

• 21.5+14.2+6.9+...-715.8

• \displaystyle{\frac{5}{3}+\frac{11}{3}+\frac{17}{3}+...+\frac{53}{3}}

4.43mins
Q5

The 15th term in an arithmetic sequence is 43 and the sum of the first 15 terms of the series is 120. Determine the first three terms of the sequence.

1.21mins
Q6

In an arithmetic sequence of 50 terms, the 17th term is 53 and the 28th term is 86. Determine the sum of the first 50 terms of the corresponding arithmetic series.

1.28mins
Q7

Determine the sum of each arithmetic series.

• 2\sqrt{7}+5\sqrt{7}+8\sqrt{7}+...+83\sqrt{7}

• x-2x-5x-...-56x

• (5a-3b)+(4a-2b)+(3a-b)+...+(-5a+7b)

• \displaystyle{\frac{2}{x}+\frac{11}{20}+\frac{27}{20}+...}

5.04mins
Q8

(a) -2-8-11-17- ...

(b) 2x^2 + 3x^2 + 4x^2 + ...

(c) a + (a + 2b) + (a + 4b)+ ...

(d) \displaystyle{\frac{17}{20} + \frac{11}{20}+ \frac{27}{20}+ ...}

0.46mins
Q9

In a grocery store, apple juice cans are stacked in a triangular display. There are 5 cans in the top row and 12 cans in the bottom row. Each row has 1 can less than the previous row. How many cans are in the display?

0.55mins
Q10

A toy car is rolling down an inclined track and picking up speed as it goes. The car travels 4 cm in the first second, 8 cm in the second second, 12 cm in the next second, and so on. Determine the total distance travelled by the car in 30 s.

0.57mins
Q11

A snowball sentence is constructed so that each word has one more letter than the previous word. An example is, "I am not cold today."

• Determine the total number of letters in the sentence.
• Write your own snowball sentence and determine the number of letters in your sentence.
0.43mins
Q12

Determine an expression for the sum of the terms of an arithmetic series where the terms are represented by t_n=3n-2.

0.46mins
Q13
• Determine x so that 2x, 3x+1, and x^2+2 are the first three terms of an arithmetic sequence.

• Determine the sum of the first 10 terms of the sequence.

2.47mins
Q14

Sweet Treats finds that its profit increases by $200 per week throughout the 16 a week summer season. Sweet Treats profit is \$1200 in the first week.

(a) Explain why the total profit for the season is represented by an arithmetic series.

(b) Determine the total profit for the season.

1.08mins
Q15

How many terms in the series 5+9+13+...+t_n are less than 500? How many terms are needed for a sum of less than 500?

3.24mins
Q17

Two arithmetic sequences , 3, 9, 15, 21, ... and 4, 11, 18, 25, ..., share common terms. For example, 81 is a term in both sequences. What is the sum of the first 20 terms that these sequences have in common?

A. 8760

B. 8750

C. 8740

D. 8770

1.39mins
Q19

Find the sum of the series 1+2+4+5+7+8+10+11+...+2999.

2.41mins
Q20

What is the value of (1^2+3^2+...+171^2)-(2^2+4^2+6^2+...+170^2)?

3.19mins
Q21

Solve 6^{x-3}-6^{x-4}=1080.

1.35mins
Q22

A geometric sequence has 1 as its first term and 2n as its last. Show that if there are 2n terms, then the product of the terms of the sequence is (2n)^n.

2.47mins
Q23

Without using a calculator, determine the sum of the first 20 terms of the sequence \displaystyle{\frac{1}{2},\frac{1}{6},\frac{1}{12},\frac{1}{20}}, ...

1.45mins
Q24
Lecture on Arithmetic Series 8 Videos

** Arithmetic Series Formula **

\displaystyle S_n = \frac{n}{2} (2a + (n-1)d) = \frac{n}{2} (t_1 + t_n)