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 483278: Find four numbers in GP whose sum is 85 and their product is 4096
Click here to see answer by mathstutor494(95)

Question 483711: how do you evaluate an infinite geometric series?
ex: 1.1+0.11+0.011+..
Click here to see answer by MathLover1(6611)

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(5390)

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(8879)

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(30945)

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(5390)

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(2518)

Question 485179: find the sum of 28 and 18
Click here to see answer by richard1234(5390)

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(788)

Question 486397: what comes next in the series of 33 34 42 69 133 ?
Click here to see answer by Tatiana_Stebko(1326)

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(5390)

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(5390)

Question 486415: sum to n terms of (1/1cube)+(1+2/1cube+2cube)+......... is
Click here to see answer by richard1234(5390)

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(3039)

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(9645)

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(3458)

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(5390)

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(5390)

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(5390)

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(3458)

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(57214)

Question 490037: what it the pattern for 120,60,180,90,blank,blank,405
Click here to see answer by MathLover1(6611)

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(9645)

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(57214)

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(30945)

Question 493683: the third and sixth terms of a geometric sequence are-75 and -9375 respectively. Find the first term, common ratio, and an explict rule for the nth term.
Click here to see answer by htmentor(788)

Question 493912: Identify the pattern and find the sixth term: 2, 5, 10, 17,____, _____,
Click here to see answer by chessace(471)

Question 494208: what is the rule for the nth term of this sequence? 2,-4,8,-10,14,-16...
Click here to see answer by chessace(471)

Question 494217: How do I find the answer to the order of operation problem -3+7+[-(9-4)]
Click here to see answer by chessace(471)

Question 494354: find a number whose product with 9 is the same as its sum with 65

Click here to see answer by Maths68(1474)

Question 494717: find convergent of 1)sinn 2)3n+5/4n+7
Click here to see answer by tinbar(128)

Question 494799: A man borrowed sum of $3600 to be redeemed in 40 installments which made an Arithmetic Progression. After paying 30 installments he died leaving behind a sum of $1200 unpaid. His heirs accepted to pay his remaining liability. What was the first installment paid by (1) The Man (2) His Heirs.

Click here to see answer by Theo(3458)

Question 494407: How do you find the 100th term in the sequence 14,28,42,56?
Click here to see answer by bucky(2189)

Question 495093: 1,4,7,10,13,16
what is the 200th number in this sequence
I am familiar with number theory, but I am stumped on finding a number that is not an even or odd, like (2n) and (2n-1)
Click here to see answer by Edwin McCravy(8879)

Question 495345: WHAT IS THE 200TH NUMBER IN THIS SEQUENCE
USE THIS SEQUENCE: 1, 4, 7, 10, 13, 16
Click here to see answer by Edwin McCravy(8879)

Question 495749: the number of different cars sold in some countries rose from 208 in 1977 to 277 in 2007. find the percent increase.

Click here to see answer by oberobic(2304)

Question 495816: If the sequence starts at 5000 and then decays by 15%, what would the common ratio be?
Click here to see answer by Alan3354(30945)

Question 495959: Hello. I would appreciate an explanation to the following question:
A playground is being designed where children can interact with their friends in certain combinations.
If there is 1 child, there can be 0 interactions.
If there are 2 children, there can be only 1 interaction.
If there are 3 children , there can be 5 interactions.
If there are 4 children, there can be 14 interactions.
Which recursive pattern represents the pattern?
asubn=asubn-1+2^(n-1)
asubn=asubn+(n-1)^2
asubn=asubn+2(n-1)
asubn=asubn+(2n-1)

So far I have figured out by setting up this basic pattern chart that:

n a
1 0 +1
2 1 +4
3 5 +9
4 14
Is the equation always the same? or does it change with the given information. I got this wrong and would appreciate understanding why? I understand how to make derive the sequence information. What if I need the 50th term? I can easily get the ninth term as in the previous question on this assignment. But having trouble understanding how to write the formula.
I appreciate you help. This is a wonderful resource for students who take math seriously because the tutors answer the questions so thoroughly. Again, thank you in advance.
Justina
Click here to see answer by Theo(3458)

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