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 481834: Find the indicated sum.

Click here to see answer by Edwin McCravy(20056)

Question 481832: The sequences are defined using recursion formulas. Write the first four terms of each sequence. a₁ = 12 and a_n = a_n-1 + 4 for n ≧ 2.

Click here to see answer by Edwin McCravy(20056)

Question 481833: Evaluate each factorial expression.
20!/2!18!
Click here to see answer by Alan3354(69443)

Question 481956: Please help me solve this question: In an arithmetic progression,the 6th term is twice the 4th term and the 3rd term is 15.Find the first term and the common difference.
Click here to see answer by solver91311(24713)

Question 481975: Continue the possible pattern. Is the pattern arithmetic, geometric, or neither. Find the 100th term.
1,16,81,256,625....
I believe this is neither arithmetic or geometric.
Click here to see answer by jim_thompson5910(35256)

Question 481995: What is the solution for the number pattern 1,4,3,6,5...?
Click here to see answer by richard1234(7193)

Question 482085: How do I solve a problem like this?!
Find the 1001st term of the arithmetic sequence:
-3,6,1,5,...
Thanks!
Click here to see answer by Alan3354(69443)

Question 482063: what is the pattern rule 2 11 38 119
Click here to see answer by Edwin McCravy(20056)

Question 482149: Pls Help me with this question urgently,thanks. Find the three numbers in a geometric progression whose sum is 28 and whose product is 512.
Click here to see answer by Edwin McCravy(20056)

Question 482464: can you please help me solve this answer 7+3c=-11
Click here to see answer by cleomenius(959)

Question 482499: So I know this should be extremely easy, but for some reason I am brain dead. Simple question, need to know how to solve.
Find the arithmetic sum 2+5+8+...+101.
Thanks!
Jessica
Click here to see answer by stanbon(75887)

Question 482605: Descibe pattern. Then write the next three numbers.
1) 640,320,160,80...
2) 4,12,36,108...
3) 1,1,2,3,5,8...
4) 2,11,38,119...
Click here to see answer by Edwin McCravy(20056)

Question 483262: How many numbers between 4000 an 5000 can be formed with the digit 2,3,4,5,6,7? How many of these numbers are divisible by 5?

Click here to see answer by josmiceli(19441)

Question 483262: How many numbers between 4000 an 5000 can be formed with the digit 2,3,4,5,6,7? How many of these numbers are divisible by 5?

Click here to see answer by mathstutor494(120)

Question 483278: Find four numbers in GP whose sum is 85 and their product is 4096
Click here to see answer by mathstutor494(120)

Question 483711: how do you evaluate an infinite geometric series?
ex: 1.1+0.11+0.011+..
Click here to see answer by MathLover1(20850)

Question 483725: In algebraic order of operations were do the parenthesis go In this equation 2+3�4-4�4 so the equation equals 64?
Click here to see answer by richard1234(7193)

Question 484324: In the arithmetic sequence, the 3rd term is 4 and the 8th term is 49. Find the 1st term, the common difference and the sum of the first ten terms.
Click here to see answer by Edwin McCravy(20056)

Question 484916: A ball rebounds 7/8 as high as it bounced on the previous bounce and is dropped from a height of eight feet. How high does it bounce on the fourth bounce and how far has it traveled after the fourth bounce?
What is the right application for this problem?

Click here to see answer by Alan3354(69443)

Question 485028: hey there, im looking for help regarding gr.11 u math, the topic is called seequences and series the question is "find the formula for the nth term that determines each sequence then list the next three terms"
thanks
Click here to see answer by richard1234(7193)

Question 485224: I am having problem with these two sequences.
118, 78, 48, 28, 18, and 2048,512,64,16,4
Click here to see answer by jorel1380(3719)

Question 485179: find the sum of 28 and 18
Click here to see answer by richard1234(7193)

Question 485370: Respected Sir / Mam ,
Please help me to solve this question. I will be very grateful for your help .
My question is :
Which term of the progression - 1, -3,-5 .... is -39 ?
As the answer given is : 20th
Please provide me the steps for this question.
Thank you

Click here to see answer by htmentor(1343)

Question 486397: what comes next in the series of 33 34 42 69 133 ?
Click here to see answer by Tatiana_Stebko(1539)

Question 486660: Twelve consecutive integers are arranged in order from least to greatest. If the sum of the first six integers is 381, what is the sum of the last six integers?
Click here to see answer by chessace(471)

Question 486410: An A.P consists of 11 terms.the middle term is 30.find the sum of the series?

Click here to see answer by richard1234(7193)

Question 486729: Q1) 11,38,136,?.... what will be the next tram?
Q2) S= root1+ root2+ root3+.....+root10000 what value of S?
Click here to see answer by richard1234(7193)

Question 486415: sum to n terms of (1/1cube)+(1+2/1cube+2cube)+......... is
Click here to see answer by richard1234(7193)

Question 486840: Find two numbers whose sum is 28 and whos product is 147
Click here to see answer by chessace(471)

Question 486860: 256, 16, 4, 2,...
Click here to see answer by checkley79(3341)

Question 486953: The question is to Multiply & Simplify the following problem
5 1/3 x 4 3/8. The answer is 70/3. The thing is I need to see the steps to know how to come to the answer. Can someone help.
Click here to see answer by josmiceli(19441)

Question 487078: An open cardboard box is 10 inches wide, 12 inches long, and 3 inches high. How many square inches of cardboard are used?
---> NEED HELP FIGURING OUT HOW TO SOLVE THIS PROBLEM..
Click here to see answer by Theo(13342)

Question 487121: What would the next two terms be in the pattern... 1, 1/2, 1/3, 1/4.... I dont understand how to get the next two terms in the sequence.
Click here to see answer by richard1234(7193)

Question 487949: How do you do the problem n=19 an=155 and d=8? in arithmetic sequence
Click here to see answer by richard1234(7193)

Question 487743: Respected Sir ,
Please help me to solve this question, I will be very grateful for your help
If the AM and HM for two numbers are 5 and 3.2 respectively then the GM will be
As the answer given is : 4.00
Please help me to simplify this !!!

Click here to see answer by richard1234(7193)

Question 488218: The sum of all terms of an infinite geometric progression is 12, and each term is three times the sum of all terms that follow it. What is the first term of the sequence?
Please help. I'm not sure if I'm following it correctly but here's what I've got so far:
Formula: S(infinity)=a1/1-r
where,
S(infinity)=12
a1=3(a2+a3+a4+..an)
And that's about it. I don't know what to do afterwards. :(
Click here to see answer by Theo(13342)

Question 489968: I'm a high school student in Algebra 2. I have a couple questions,
1. what are the formulas to find the nth term of an arithmetic and geometric sequence? here is a problem im having trouble with..
write a formula for the nth term of an arithmetic sequence, then a25.
d=2 a12=18
an=_____
a25=_____
I'm not really confident on how to find the answer :(
Another question I have is how to find the sum..
ex. find the sum of the first n terms when n=20.
arithmetic series: 40+37++34+31+....
then im supposed to find n for Sn=195, how do i do that??
thanks for the help!
Click here to see answer by stanbon(75887)

Question 490037: what it the pattern for 120,60,180,90,blank,blank,405
Click here to see answer by MathLover1(20850)

Question 491008: Find A sub n for this geometric sequence.
a sub 1=2,400, r=1/4, n=7
I knew how to do this.. but now i am totally lost about finding a sub n..
I know the equation and stuff----> An=A1 x r^n-1
but for some reason I can't figure it out....
help me please :)
Click here to see answer by ccs2011(207)

Question 491118: how do you solve for 4x+3y=180 my teacher gave us the hint that x= 15 and that y=40 but i cant figure out the steps
Click here to see answer by josmiceli(19441)

Question 492675: The first difference of a sequence is 3, 6, 9, 12, 15...
Find the first six terms of the original sequence in each of the following cases:
a. The first term of the original sequence is 3.
b. The sum of the first two terms of the original sequence is 7.
Click here to see answer by chessace(471)

Question 493439: I need to fine the first five terms of the sequence with the rule an=3+(n-1)1/2
Click here to see answer by stanbon(75887)

Question 493480: A plant supervisor reported that of the 20 people being supervised, 16 could operate a lathe, 12 could operate a grinder, 8 could operate a lathe and a bender, 5 could operate all 3 machines. Should the supervisor be believed? Why or why not?
PLEASE help. I am desperate.
Click here to see answer by scott8148(6628)

Question 493614: using the digits 1,2,3,4 write an expression for 39
Click here to see answer by Alan3354(69443)

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