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 1077016: Twice a number added to 9 is 15. Find the number
Click here to see answer by josgarithmetic(39617)

Question 1077087: The probability tha a student does his homework 0.1, if he goes out with friends,and 0.6 if he does not go out with friends.the probability that a student goes out with friends is 0.75.What is the probability that the student does his homework?
Click here to see answer by Theo(13342)

Question 1077136: Evaluate the following sum
Sn=1/1*4+1/2*5+1/3*6+.......+1/n(n+3)
Click here to see answer by ikleyn(52787)

Question 1077411: to find series where An=n+4 where a1=3
Click here to see answer by ikleyn(52787)

Question 1077338: Enter the first four terms of the sequence defined by the rule given
f(1)=8,f(n)=f(n-1)-3
Click here to see answer by ikleyn(52787)

Question 1077457: 3term is 5 and 7 term is 9 find 17 th term
Click here to see answer by ikleyn(52787)

Question 1077321: A supermarket finds that the number of boxes of a new soda drink sold increases each week. In the first week, only 24 boxes of the soda drink were sold. In the next week, 56 boxes of the soda drink were sold and in the third week 88 boxes of the soda drink were sold. The number of boxes of soda drink sold each week represents an arithmetic sequence.
What is the explicit rule for the arithmetic sequence that defines the number of boxes of soda drink sold in week n?

Click here to see answer by josgarithmetic(39617)

Question 1077673: 2, 5, 16, 57 ,?
Click here to see answer by ikleyn(52787)

Question 1077683: I need help to work out this sequence and HOW:
14 7 12 8 10 9 _ _
WHAT NUMBER COMES NEXT
Click here to see answer by Alan3354(69443)

Question 1077508: The cost of heating the Charpentier's house in October is $250. As winter progresses, the price increases $30 each month. How much does the family pay to heat their home for 5 months
Click here to see answer by josgarithmetic(39617)

Question 1077744: the 16th term of an a.p is 93, given that each common
difference is 6,find the first and 28th term
Click here to see answer by josgarithmetic(39617)

Question 968110: how many ways there are to remove three elements from the sequence 1 4 2 5 7 3 8 9, so that the remaining from an increasing sequence

Click here to see answer by quixote(1)

Question 1077752: if a^2+b^2=4
and b is not 1 nor 2 or rational number with it is not also true for 2^1/2 then proof that (a^1/2)/b^3+3a^4=ab^1/4*1/2^1/2
Click here to see answer by ikleyn(52787)

Question 1077763: Find P if P-3, 3P+5 and 18P -5 are three consecutive terms of a GP
Click here to see answer by amfagge92(93)

Question 1078006: Find the number that is 1/3 of the way from 3/5 to 11/16.
Click here to see answer by josgarithmetic(39617)

Question 1078081: what is the solution to the sequence 7, 21, 8, 72, 9.?
Click here to see answer by Fombitz(32388)

Question 1078080:
Click here to see answer by Alan3354(69443)

Question 1078235: Convert a normal distributed score of 89 with a mean of 85 and a standard deviation of 4 into a z-score. .. I forgot my calculator at home help
Click here to see answer by Boreal(15235)

Question 1078234: Over the years a dog trainer noticed that the mass of the dogs he was training were normally distributed. They had a mean mass of 11.2 kg and a standard deviation of 2.8 kg. If he trained 200 dogs this month, how many of them would be between 8.4 kg and 11.2 kg?
Click here to see answer by Boreal(15235)

Question 1078436: What is the explicit rule for the sequence?

34,26,18,10, �

an=26−8n
an=42−8n
an=34n+42
an=34n−26
Click here to see answer by ikleyn(52787)

Question 1078436: What is the explicit rule for the sequence?

34,26,18,10, �

an=26−8n
an=42−8n
an=34n+42
an=34n−26
Click here to see answer by Boreal(15235)

Question 1078437: When the town of Manning first started its voluntary recycling program, 2500 of the town�s residence participated. The town predicts that the number of people participating in the recycling program will increase by 5% each year.
Which explicit rule can be used to determine the number of people participating in the program in the fifth year?

an=2500(1.05)n
an=2500(0.05)n−1
an=2500(0.05)n
an=2500(1.05)n−1

Click here to see answer by Boreal(15235)

Question 1078435: The sales of homes in a new development have been increasing. In January, 5 homes were sold, in February,
12 homes were sold. In March, 19 homes were sold. This pattern continued for the remainder of the year.
What is the explicit rule that can be used to find the number of homes sold in the nth month of the year?

an=7n+2
an=7n−5
an=7n−2
an=7n+5
Click here to see answer by ikleyn(52787)

Question 1078519: HELP ME??
Because of the friction and air resistance, each swing of a pendulum is a little shorter than the previous one. The lengths of the swings form a geometric sequence. Suppose the first swing on the pendulum has an arc length of 100cm and a return swing of 99cm.
a) On which swing will the length first have a length less than 50 cm?
b) Find the total distance traveled by the pendulum until it comes to rest.
Click here to see answer by htmentor(1343)

Question 1078542: What is ∑n=14[100(−4)n−1] equal to?

Enter your answer in the box.
Click here to see answer by ikleyn(52787)

Question 1078518: PLEASE HELP
A diamond is purchased for $2300 on 1/1/2002. Its value increases 5% each year. Find the value of the diamond on 1/1/2009.
Click here to see answer by josmiceli(19441)

Question 1078683: The sixth term of a geometric series of positive terms
is 10 and the sixteenth term is 0.1, what is the eleventh term?

Click here to see answer by akch2002(12)

Question 1078683: The sixth term of a geometric series of positive terms
is 10 and the sixteenth term is 0.1, what is the eleventh term?

Click here to see answer by Edwin McCravy(20056)

Question 1078796: 14, 8, 9, 14, 5, 30,..... find next term.?
Click here to see answer by ikleyn(52787)

Question 1078795: 5, 7,18, 47, 105 find the next term.?
Click here to see answer by ikleyn(52787)

Question 1078765: 1 I 2 L 3 F 4
Click here to see answer by ikleyn(52787)

Question 1079451: the first term of an arithmetic sequence is -5, and the twelfth term is 17 find the common difference
Click here to see answer by ikleyn(52787)

Question 1079599: a series has first term 7 and 5th term 23. find the common difference , 15th term and sum of the first 10 terms.
Click here to see answer by amfagge92(93)

Question 1079634: Hi , I've been stuck on this problem I've found online and I just can't crack it.
I was given a sequence :
8,0,8,16,24,16,1, -whats the next number?
The awnser to this is 40, but Im clueless as to why . I would be verry happy if you could help me with this.
Thank you !
Hadar
Click here to see answer by MathLover1(20850)

Question 1079638: using the method of successive differences, find the 8th term: 4, 37, 180, 793, 2566, 6659, 14842

Click here to see answer by solver91311(24713)

Question 1080200: What is the general formula for the pattern 1;9;25;49
Click here to see answer by Fombitz(32388)

Question 1080200: What is the general formula for the pattern 1;9;25;49
Click here to see answer by amfagge92(93)

Question 1072885: The total oil reserve at the Kranka oil field is 250 tonnes. The annual consumption is 20 tonnes which increases by 2% per annum. How long will it take for the oil to be used up?
Click here to see answer by jorel1380(3719)

Question 1077345: find the length of a cord stretched on the 5th bounce, when Nora jumps. her initial stretch length was 140' and the stretch decreases by 70% each time in a geometric sequence. round to the nearest tenth.
i tried the equation: a5= 140�0.7^5-1 and got an answer of 33.6.
but then when i subtracted 70% from each bounce, i ended up with 1.1.
im confused on what i did wrong
Click here to see answer by jorel1380(3719)

Question 1080556: The sum of two complex numbers is (-7 + 7i). If one of the numbers is (3-5i), what is the other number?
Click here to see answer by amfagge92(93)

Question 1080574: what is gm of sequence 1,2,4,8...2^n
Click here to see answer by rapture(86)

Question 1080574: what is gm of sequence 1,2,4,8...2^n
Click here to see answer by MathTherapy(10552)

Question 1080580: What is the 30th term and how do u work it out?
Click here to see answer by rapture(86)

Question 1080710: some sequence involve a parten but neither arithemetic nor geometric considering the following sequence 6,8,2,-6,-8,-2, 6, 8,.....
(i). find the sum ofthe first 72 terms
(ii).find the sum of the first 73 terms
Click here to see answer by Boreal(15235)

Question 1080712: without nesessary expanding find the term tha does not contain valiable x in the expansion of (3x^2-1/4x)^6
Click here to see answer by Boreal(15235)

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