math(need 2nd opinion)
posted by Jon .
1)Find a1 in a geometric series for which Sn=300,r=3,and n=4
A)15
B)15/2
C)15
D)1/15
I chose A
2)Find the sum of the infinite geometric series. Sigma sign with infinity symbol above and n=1 below. To the right 20(1/4)n1
A)25
B)80/3
C16
D)does not exist
I chose A
3)Find the sum of the infinite geometric series:4+3+9/4+:...
A)16/7
B)16
C)12
D)does not exist
I chose B
4)Write 0.72 repeating as a fraction.
A)7/9
B)8/11
C)18/25
D)7 and 2/9
I chose B but my book confuses me on how to work it out. I just divided 8 and 11 and I got .72 repeating
5)Find the fifth term of the sequence in which a1=3,and aN+1=3aNn
A)301
B)99
C)193
D)341
I don't know

math(need 2nd opinion) 
Ms. Sue
Please note Damon's last post.
math  Jon, Wednesday, December 12, 2007 at 5:43pm
thanks for the help. are you possitive they are correct?
math  Damon, Wednesday, December 12, 2007 at 5:48pm
Oh good heavens, always check anything I do! 
math(need 2nd opinion) 
drwls
3. 4+3+9/4+:... = 4(1 + (3/4) + (3/4)^2^3 + ...]
= 4*[1/(13/4)] = 16
4. There is nothing wrong with trying the multiple choices and seeing which one works. That is what you did. There is a direct way also.
Let X = 0.727272...
0.727272...(0.01)X = 0.727272..0.0072727..)
= 0.720000...
Therefore
X  0.01X = 0.72
0.99 X = 0.72
X = 72/99 = 8/11
Respond to this Question
Similar Questions

algebra
1)Find a1 in a geometric series for which Sn=300,r=3,and n=4 a.15 b.15/2 c.15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(1/4)n1 on the right side a.25 b.80/3 c.16 … 
algebra(check)
1)Find a1 in a geometric series for which Sn=300,r=3,and n=4 a.15 b.15/2 c.15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(1/4)n1 on the right side a.25 b.80/3 c.16 … 
algebra
1)Find a1 in a geometric series for which Sn=300,r=3,and n=4 a.15 b.15/2 c.15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(1/4)n1 on the right side a.25 b.80/3 c.16 … 
algebra
1)Find a1 in a geometric series for which Sn=300,r=3,and n=4 a.15 b.15/2 c.15 d.1/15 answer=a 2)Find the sum of the infinite geometric series n=1 at the bottom of the sigma notation 20(1/4)n1 on the right side a.25 b.80/3 c.16 … 
Calculus III
Which of the following series are geometric series? 
math
1)Find the sixth term of the geometric sequence for which a1=5 and r=3 A)1215 B)3645 C)9375 D)23 I chose A 2)Write an equation for the nth term of the geometric sequence 12,4,4/3... A)aN=12(1/3)n1 B)aN=12(1/3)n1 C)aN=12(1/3)n+1 … 
math
1)Find a1 in a geometric series for which Sn=300,r=3,and n=4 A)15 B)15/2 C)15 D)1/15 I chose A 2)Find the sum of the infinite geometric series. Sigma sign with infinity symbol above and n=1 below. To the right 20(1/4)n1 A)25 B)80/3 … 
PreCalculus
Q.Determine the sum of each infinite geometric series. t_1= 8 r = 2^1/2  A.This is a divergent series because the absolute value of r is greater than 1.  … 
Geometric Series
Evaluate the geometric Series or state that it diverges lower bound k= 1 upper bound = infinity E (sum symbol) E 5(1/6)^(5k) I know it converges but im not sure to what 
math(geometric series)
the common ratio of the infinite geometric series whose 2nd term is 3/2 and its sum is 8?