More Practice
1. Using the formula for finding a term in an arithmetic sequence, find four arithmetic means
between 8 and 184. (You are not required to leave your answer in fraction form – because
this decimal terminates)
2. Using the formula for finding the nth term in a geometric sequence, find the 11th term if
a1 = 936 and r = 1/3.
3. Given an = 2an-1 + 7 and a1 = -4, find the first four terms of the sequence.
4. In a geometric sequence a1 = 460 and r = 4/5, using the formula for finding a particular term
in a geometric sequence, what term is 1929379840?
48828125
5. Using the formula for the sum of the first n terms in an arithmetic sequence, find the sum of
the first 72 terms in the series 2 + 7 + 12 + …
6. Find 3 geometric means between 2 and 200 and state the r-value.
7. Find the third and fourth term of the sequence defined by the formula An = 2(n - 3)(n + 4).
8. Given the arithmetic sequence with A5 = 12 and A11 = 102, find the value of A1, d, A231 and
S400.
9.
In a geometric series A1 = 4 and A17 = 256, using the formula for finding the nth term in a
geometric sequence, find A49.
5
10. Find the sum of the series indicated by ∑ (3k + 7)
k=1
11. Given the series 90 + - 60 + 40 +…, using the proper formula, find S7 and leave your answer
in fraction form.
12. Write the following sum using sigma notation: 3 + 7 + 11 + 15 + 19 + 23 + 27.
13. Given n = 18, d = -5 and A4 = 13, using sigma notation represent the given information and
find the sum of the first 18 terms.
14. Find the sum of the first eight terms of the geometric series whose first term is -4 and eighth
term is
2187
.
32
15. Find the 22nd term of the geometric sequence given A1 = 64 and A8 = ½ .
16. In a geometric sequence, A8 = 100 and r = 5, find the exact values of A1 and the sum of the
first eight terms.