All Questions: Geometric Sequences and Series
Theory
MCQ
01.
Theory 4 Marks
Finding the nth Term and Sum of n Terms, Geometric Sequences

The first three terms of a geometric sequence are $3m - 4$, 6, and $m + 1$, where $m$ is an integer. Prove that $m$ satisfies the equation $3m^2 - m - 40 = 0$.

02.
Theory 6 Marks
Finding the nth Term and Sum of n Terms

In a geometric sequence, the third term, $t_3$, is 64, and the seventh term, $t_7$, is 1024.

1. What is the common ratio of this sequence?
2. Determine the first term, $t_1$, of the sequence.
3. Find the total sum of the first 10 terms of the sequence.

03.
Theory 6 Marks
Finding the nth Term and Sum of n Terms, Geometric Sequences

Given that $a$, $3a$, and $a + 40$ are consecutive terms of a sequence:

(i) What is the value of $a$ if this sequence is geometric?

(ii) List the three terms of the sequence and identify the common ratio.

04.
Theory 7 Marks
Finding the nth Term and Sum of n Terms, Combinations

Consider the sequence $$S_n = \frac{1}{3} + \frac{1}{9} + \frac{1}{27} + \frac{1}{81} + \dots + \frac{1}{3^n}$$.

(a) Calculate $S_1, S_2, S_3, S_4,$ and $S_5$ in fractional form.

(b) Based on your calculations, hypothesize a formula for $S_n$.

(c) Determine $S_n$ using the formula $$S_n = \frac{u_1(1 - r^n)}{1 - r}$$.

(d) Discuss the behavior of $S_n$ as $n$ becomes very large.