Questions on Algebra: Sequences of numbers, series and how to sum them answered by real tutors!

Tutors Answer Your Questions about Sequences-and-series (FREE)

Question 877253: What is the 17th term in the arithmetic sequence in which a^6 is 101 and a^9 is 83?
Click here to see answer by richwmiller(17219)

Question 880398: P,6 and r are three consecutive terms of a linear sequence.
if r is twice the value of p,find the value of p and r
Click here to see answer by ewatrrr(24785)

Question 880017: in an arithmetic sequence the ratio of first term to second term is 2:3 .what is the ratio of third to fifth term?
Click here to see answer by richwmiller(17219)

Question 880342: Deon drove 260 miles using 12 gallons of gas. At this rate, how many gallons of gas would he need to drive 286 miles?
Click here to see answer by fcabanski(1391)

Question 880530: is 1/16 lies between 1/4 and 1/8? how?
Click here to see answer by josgarithmetic(39617)

Question 880054: Write a recursive formula for the sequence 15, 11,7, 3, -1, -5,.....
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Question 880042: Find the common difference, the fourth term, and the "n"th term in the arithmetic sequence 80,76,72,....
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Question 880702: what is the third term in the expansion of (2x-3y)^3

Click here to see answer by jim_thompson5910(35256)

Question 880702: what is the third term in the expansion of (2x-3y)^3

Click here to see answer by Alan3354(69443)

Question 880739: the sum of the first two terms of an arithmetic sequence is 16, and the sum of the second and third term is 28, determine the first three terms
Click here to see answer by josgarithmetic(39617)

Question 880734: A student has 3 different shirts, 2 different pairs of pants, and 4 pairs of shoes. How many different outfits consisting of one pair of pants, one shirt, and one pair of shoes can be made from this selection?
Click here to see answer by rfer(16322)

Question 880744: By how much does the arithmetic mean of 4 and 9 exceed the absolute value of their geometric mean?
Click here to see answer by Fombitz(32388)

Question 880834: Having trouble with infinite series... Actually with all algebra. But,
Question: Find the sum of these infinite series. If it is not possible, write "no sum" and explain why.
1) 1024 + 512 + 256 +128 + ...
2) 1/9 + 1/3 + 1 + 3 +...
3) 16 + 4 + 1 + 1/4 +...
Click here to see answer by richwmiller(17219)

Question 878674: sum of series terms is
a.
b.9841
c.9841/root3
d.none of these
Click here to see answer by richwmiller(17219)

Question 880917: In a geometric progression of positive terms, the 5th term is 9 times the 3rd term and the sum of the 6th and 7th terms is 972. Find the
a) common ratio
b) sum of the first 6 terms
Click here to see answer by richwmiller(17219)

Question 880912: Find the term of the geometric square.
The first term of a geometric sequence is 5 and the common ration is 3. Write the explicit formula for the sequence. Whats the 12th term of the sequence.

thank you for your help need answers ASAP i appreciate it
Click here to see answer by richwmiller(17219)

Question 880045: Need to write the series in sigma notation
3+6+11+18+27
Click here to see answer by richwmiller(17219)

Question 880064: Use summation notation to express the sum.
5+20+80+......+20,971,520
Click here to see answer by richwmiller(17219)

Question 878904: 1. Choose the odd numeral pair/group.
(A) 8 (34) 9 (B) 48 (120) 12 (C) 7 (144) 11 (D) 20 (270) 115
2. ? � 43 � 43 = 43 � 43 + 12 � 43
The missing number in the box is _______?
(A) 12 (B) 54 (C) 56 (D) 98
3. A right circular cone has radius 5 cm and height 8 cm.
What is the lateral surface area of the cone?
(A) 40p sq cm (B) 445p sq cm (C) 5p 39 sq cm
(D) 5p 89 sq cm.

Click here to see answer by richwmiller(17219)

Question 879998: write the nth rule if r=5, a2=200
Click here to see answer by richwmiller(17219)

Question 881022: I need help. Really don't understand this.
Choose the correct eighth term of the sequence A(n)=1/2(-3)^(n-1).
Then there's: A)364.5 B)-1093.5 C)-121.5 D)3280.5
Can I have somewhat of an example on how to do this? Please?
Click here to see answer by jim_thompson5910(35256)

Question 880991: how many terms of the series 4+6+8+10... add to 180
Click here to see answer by josgarithmetic(39617)

Question 881055: Which is the next in the sequence 130, 120, 110, 100, 90, ______?
Click here to see answer by Fombitz(32388)

Question 881057: a ball is dropped from height of 20m. it rebounds 4_5 of its height after each bounce. Find the total distance travelled by the ball when it touched the floor on the 3rd bounce
Click here to see answer by Boyen(12)

Question 881058: the fifteenth 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.
Click here to see answer by dkppathak(439)

Question 881327: Find the first four terms of the sequence an=n(n+7).

Click here to see answer by Fombitz(32388)

Question 881344: Find the sum of the infinite geometric series 5 plus five-thirds plus five-ninths + five twenty sevenths etc. , if it exists.
Click here to see answer by richwmiller(17219)

Question 881303: find out a number from a series like this- 12,13,1213,121312,1313,1212,121212,131313
number can be anything

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Question 881581: if the rage of set of numbers {150,90,125,110,170,155,x,100,140} is 95 what could be the value of x
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Question 881580: x is a integer such that 2x is a factor of 12!,what is the greatest possible value of x
Click here to see answer by ewatrrr(24785)

Question 881613: Dear Sir/Madam;
Kindly help me with this question: The sum of the first 50 terms of an arithmetic progression is 200 and the sum of the next 50 terms is 2700. Find the first term. Thanks a lot!
Click here to see answer by richwmiller(17219)

Question 877252: The first three terms of an arithmetic sequence are 2x-1;3x;5x-2........i found x as 3...calculate the sum of the first 21 terms of the sequence
Click here to see answer by richwmiller(17219)

Question 881838: what number comes next in this series 2,3,4,8,9,10,20,21,22
Click here to see answer by stanbon(75887)

Question 881559: Q:if the fourth term i.e (a4)= 4 ,then find the sum of first seven terms of the corresponding arithmetic series
Click here to see answer by richwmiller(17219)

Question 881622: Dear Sir/Madam:
A pleasant day!I have a math problem here involving arithmetic sequence Given a sequence a1 , a2 , a3 ................. an and if a4=4 and a6=6 and an=an-1 + an-2 for n=1, 2, 3�� Find an
Click here to see answer by richwmiller(17219)

Question 881938: Can you please show me how to work this out? I would really be thankful!!
What is the sum of the arithmetic sequence 3, 9, 15..., if there are 26 terms?
1,452
1,728
2,028
2,268

Click here to see answer by ewatrrr(24785)

Question 882020: find the first term if n=20, d=4 and L=80
Click here to see answer by richwmiller(17219)

Question 882016: A+B+C+D=36
Click here to see answer by richwmiller(17219)

Question 882189: 4n+4 (n'th term 10) we assume it is 4x10 + 4 is this assumption correct?
Click here to see answer by Simnepi(216)

Question 882391: Tell 5 numbers whose sum will be 30 by using number
Click here to see answer by richwmiller(17219)

Question 882417: please do help me about this :) the units digit of a three-digit number is represented by x.if the other two digits are represented by 3x and 4x represent the product of the digits of the number, what is the smallest three-digit number that may be formed? what is the largest three-digit number?
Click here to see answer by ankor@dixie-net.com(22740)

Question 882707: Dear Sir/Madam;
Good day! Can you please help me with this question about geometric series. Here it is: A town has an original population of 100,000 and increases by 3% each year. How long will it take for the population to double?

Thank you very much for your help!
Click here to see answer by Fombitz(32388)

Question 882681: 13, 18,14,15,16,13,19 .....what is the next number in the series? what is the rule applied for this series.

Click here to see answer by richwmiller(17219)

Question 882731: Dear Sir/Madam;
Good day! Please help me with this series question:
A piece of paper is 0.01 inch thick. It is cut and stacked repeatedly in such a way that its thickness is doubled each time for 20 times. How thick is the result?
Thank you so much for your help!
Click here to see answer by Leaf W.(135)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755, 10756..10800, 10801..10845, 10846..10890, 10891..10935, 10936..10980, 10981..11025, 11026..11070, 11071..11115, 11116..11160, 11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790