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 824387: Please find the correct replacement for the question mark 1,2,6,24?

Click here to see answer by richwmiller(17219)

Question 824545: The sum of three consecutive multiples of 6 is 126.Find these three multiples.
Click here to see answer by Alan3354(69443)

Question 824720: The missing number in the series
40, 120, 60, 180, 90, ?, 135 is
(A) 110 (B) 270
(C) 105 (D) 210
Click here to see answer by checkley79(3341)

Question 824706: Please help me with this.
1) The first and last term of a geometric series are 2 and 2048 respectively. The sum of the series is 273 a) find the number of terms
b) find the common ratio
Thanks for your help.
Click here to see answer by jsmallt9(3758)

Question 824741: which is the next number in the sequence 244,123,62,31
Click here to see answer by stanbon(75887)

Question 824889: find the tenth term in the expansion of (x+3)^12
Click here to see answer by Edwin McCravy(20056)

Question 824865: What should be added to make it 100. Take numbers between 4-38 only 5 digits required. Every number is at the distance of 4
Click here to see answer by Edwin McCravy(20056)

Question 825036: in this series 6,4,1,2,2,8,7,4,2,1,5,3,8,6,2,2,1,4,1,3,5,8,6,how many pairs of successive numbers have a difference of 2 each ?

Click here to see answer by Edwin McCravy(20056)

Question 825102: Write and explicit formula for 2, 10, 18, 26
Click here to see answer by josgarithmetic(39617)

Question 825119: What is the average of seven numbers, preceding 7, each decreasing by 1/2?
Click here to see answer by math-vortex(648)

Question 825128: Sequence: 1, 9, 25, 49, ...
a) Find a6
b) Find an
each number is the square of each odd consecutive number (1, 3, 5, 7, ...) and a6 = 121 but there has to be algebraic work to show how a6 = 121
my teacher's really vague about work but my guess she wants a rule that you can use to solve this sequence. I can't spot the common difference/ratio.
all i have so far is a6=5d+1 or a6=r^5
i know how to determine if this is an arithmetic or geometric sequence but this ones confusing me :(
Click here to see answer by Alan3354(69443)

Question 825150: find the 10th of the G.P 7, 14, 28, ........?
Click here to see answer by KMST(5328)

Question 825175: Hi i need help for this question can anyone help me...
In an arithmetic sequence, the sum of the first term term is 125 and the third term is 5. How to find the first term and the common difference?
Thanks for helping mates ^_^
Click here to see answer by KMST(5328)

Question 825149: divide 105 into two parts such that one half of the first exceeds one fifth of the second by 35. find the number.

please help me to solve this.
Click here to see answer by richwmiller(17219)

Question 825215: a geometric sequence has a sixth term of 24 and a common ratio of 2/3. find the first three terms

Click here to see answer by josgarithmetic(39617)

Question 825215: a geometric sequence has a sixth term of 24 and a common ratio of 2/3. find the first three terms

Click here to see answer by MathTherapy(10552)

Question 825241: Frieda is keeping track of how many coupans she has savved on a piece of paper . she spilled some coffe on the paper. her lis now looks like this: blank represents where the coffee spill occured.
Started : 30 coupon After 1 week: after 2 weeks: after 3 weeks : 240 coupons
a. assume that the sequence of the number of coupons is arithmetic.How many coupon did she have after 1 week? 2 weeks?
b. Assume that the sequence of the number of coupons is geometric. How many coupons did she have after 1 week? after 2 weeks?
Click here to see answer by stanbon(75887)

Question 825240: . Kelly's art teacher is modeling a project for art and algebra.The students are going to create a project with blocks in a patteren. Students will use algebra to describe the pattern. A student puts two formulas on the board. Recursive:f(0)=3, f(n)=2*f(n-1)
Explict: f(n)=3*2^n
a. using the recursive formula above,write the first 5 terms of the sequence.
b.You want to know the value of f(30). Is it more efficent to use the recursive or explicit formula? Explain your answer.
Click here to see answer by stanbon(75887)

Question 825250: Find the 43rd term of the sequence an+ 4n-1, where n represents the nth term.
what i think you have to do is an=4(43)-1
But i dont think that is correct and would like your help!
Thank you
Click here to see answer by stanbon(75887)

Question 825401: Heather is collecting dimes. She saves one dime on the first day, two dimes on the second day and three dimes on the third day. If this pattern continues, how much money will she have saved at the end of 30 days?
What algebraic formula would I use for this?
Click here to see answer by jsmallt9(3758)

Question 825369: The first and last term of a geometric series are 2 and 2048 respectively. The sum of the series is 273. Find the common ratio and the number of terms.

Click here to see answer by jsmallt9(3758)

Question 825537: Hi, I have to find the general formula for the sequence 2 3 5 8 14 19 and so on, i.e. first 3-2=1, then 5-3=2, 8-5=3, etc, so the difference is simply 1,2,3,4,etc. That means the next number after 19 would be [(19-14)+1]+19 = 25, but the general formula a_n = ???
I guess its fairly easy but I can't see it, and google doesn't help either!
Thanks in advanced!
Click here to see answer by Edwin McCravy(20056)

Question 824901: if the nth term of an A.P. is 6n-1, then find its 50th term.
Click here to see answer by tommyt3rd(5050)

Question 824523: the first and last term of an arithmetic progression are -30 and 10 respectively. find the arithmetic progression and it's 20th term.
Click here to see answer by tommyt3rd(5050)

Question 825637: Your job pays $6 an hour. Write a variable expression for your pay in dollars for working h hours. Okay I tried my best but I am not sure because I dont no what a variable expression is but I got h(6)
Click here to see answer by josgarithmetic(39617)

Question 825883: please provide the next number is sequence 56,00,53,???
Sir its very urgent Plz. Plz. and Send me email plz.
thank you in advance
Nikhil TKD From India
Click here to see answer by Alan3354(69443)

Question 825921: how to find T1 (first term) in sequence or series when T1 isnt given but say t2 and t4 is or something related to that
Click here to see answer by jsmallt9(3758)

Question 825977: The sum of two numbers exceeds their dierence by 12. If their product is 102, what are the
numbers?
Click here to see answer by josgarithmetic(39617)

Question 826059: These are the first 4 numbers of a sequence:
1 3 6 10 ...
Explain how to find the nth term of this sequence.
Click here to see answer by rfer(16322)

Question 825985: what is the next no in the series 42,56,51

Click here to see answer by math-vortex(648)

Question 826079: Hello Sir, Alan3354(35133
I know its not enough numbers But plz. you try.
I am give you more numbers 56,00,53,52,??? And 03,97,29,09,???
its 2 series plz. you try plz.

Nikhil Tkd
Click here to see answer by Alan3354(69443)

Question 826123: Calculation of the following:
1+2+3+4....+97+98+99+100
I tried an arithmetic sequence a=1(100-1)1 but it wont work.
Click here to see answer by richwmiller(17219)

Question 826123: Calculation of the following:
1+2+3+4....+97+98+99+100
I tried an arithmetic sequence a=1(100-1)1 but it wont work.
Click here to see answer by stanbon(75887)

Question 826123: Calculation of the following:
1+2+3+4....+97+98+99+100
I tried an arithmetic sequence a=1(100-1)1 but it wont work.
Click here to see answer by MathTherapy(10552)

Question 818578: find the sum of the 181st term to the 144th term in an arithemeti sequence 1,5,9
Click here to see answer by tommyt3rd(5050)

Question 818833: The first and last term of the arithmetic progression are 3 and 21 respectively and the sum of the series is 240. Find the number of terms.
Click here to see answer by tommyt3rd(5050)

Question 820752: 1 4 13 25 41 61 85 113 wrong number in the series
Click here to see answer by tommyt3rd(5050)

Question 822522: A+B=140
B+C=160
C+D=130
D+A=110

Click here to see answer by tommyt3rd(5050)

Question 826479: Rewrite this sum in sigma notation, starting at n=1
1-x+x^2-x^3+....+x^2k
Thanks!!
Click here to see answer by jsmallt9(3758)

Question 826563: In the following series which comes next 0,5,22,57,?,205.Please provide explanation for this question.
Click here to see answer by stanbon(75887)

Question 826650: The product of two whole numbers is 90. One number is 2.5 times as great as the other. What are the two numbers?
Click here to see answer by MathLover1(20850)

Question 826711: Show that in any GP, S(2n): S(n)=(r^n+1):1
Thanks!
Click here to see answer by Edwin McCravy(20056)

Question 826918: 2, 12, 36,80,150,? With proper solution
Click here to see answer by stanbon(75887)

Question 826918: 2, 12, 36,80,150,? With proper solution
Click here to see answer by MathLover1(20850)

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