The first three terms of an arithmetic progression are \(\frac{p^2}{6}\), \(2p - 6\) and \(p\).
(a) Given that the common difference of the progression is not zero, find the value of \(p\).
(b) Using this value, find the sum to infinity of the geometric progression with first two terms \(\frac{p^2}{6}\) and \(2p - 6\).
The 1st, 3rd and 13th terms of an arithmetic progression are also the 1st, 2nd and 3rd terms respectively of a geometric progression. The first term of each progression is 3. Find the common difference of the arithmetic progression and the common ratio of the geometric progression.
A ball is such that when it is dropped from a height of 1 metre it bounces vertically from the ground to a height of 0.96 metres. It continues to bounce on the ground and each time the height the ball reaches is reduced. Two different models, A and B, describe this.
Model A: The height reached is reduced by 0.04 metres each time the ball bounces.
Model B: The height reached is reduced by 4% each time the ball bounces.
(i) Find the total distance travelled vertically (up and down) by the ball from the 1st time it hits the ground until it hits the ground for the 21st time,
(a) using model A,
(b) using model B.
(ii) Show that, under model B, even if there is no limit to the number of times the ball bounces, the total vertical distance travelled after the first time it hits the ground cannot exceed 48 metres.
Three geometric progressions, \(P, Q\) and \(R\), are such that their sums to infinity are the first three terms respectively of an arithmetic progression.
Progression \(P\) is \(2, 1, \frac{1}{2}, \frac{1}{4}, \ldots\).
Progression \(Q\) is \(3, 1, \frac{1}{3}, \frac{1}{9}, \ldots\).
(i) Find the sum to infinity of progression \(R\).
(ii) Given that the first term of \(R\) is 4, find the sum of the first three terms of \(R\).
The first term in a progression is 36 and the second term is 32.
(i) Given that the progression is geometric, find the sum to infinity.
(ii) Given instead that the progression is arithmetic, find the number of terms in the progression if the sum of all the terms is 0.
The 1st, 2nd and 3rd terms of a geometric progression are the 1st, 9th and 21st terms respectively of an arithmetic progression. The 1st term of each progression is 8 and the common ratio of the geometric progression is \(r\), where \(r \neq 1\). Find
(i) the value of \(r\),
(ii) the 4th term of each progression.
The first 2 terms of a geometric progression are 64 and 48 respectively. The first 3 terms of the geometric progression are also the 1st term, the 9th term and the nth term respectively of an arithmetic progression. Find the value of n.
The first term of an arithmetic progression is 12 and the sum of the first 9 terms is 135.
(i) Find the common difference of the progression.
The first term, the ninth term and the nth term of this arithmetic progression are the first term, the second term and the third term respectively of a geometric progression.
(ii) Find the common ratio of the geometric progression and the value of n.
The first and second terms of a progression are 4 and 8 respectively. Find the sum of the first 10 terms given that the progression is
(i) an arithmetic progression,
(ii) a geometric progression.
A television quiz show takes place every day. On day 1 the prize money is $1000. If this is not won the prize money is increased for day 2. The prize money is increased in a similar way every day until it is won. The television company considered the following two different models for increasing the prize money.
Model 1: Increase the prize money by $1000 each day.
Model 2: Increase the prize money by 10% each day.
On each day that the prize money is not won the television company makes a donation to charity. The amount donated is 5% of the value of the prize on that day. After 40 days the prize money has still not been won. Calculate the total amount donated to charity
(i) if Model 1 is used,
(ii) if Model 2 is used.
A progression has a second term of 96 and a fourth term of 54. Find the first term of the progression in each of the following cases:
(i) the progression is arithmetic,
(ii) the progression is geometric with a positive common ratio.
The first term of a geometric progression is 216 and the fourth term is 64.
The second term of the geometric progression is equal to the second term of an arithmetic progression.
The third term of the geometric progression is equal to the fifth term of the same arithmetic progression.
Find the sum of the first 21 terms of the arithmetic progression.
The first term of an arithmetic progression is 8 and the common difference is \(d\), where \(d \neq 0\). The first term, the fifth term and the eighth term of this arithmetic progression are the first term, the second term and the third term, respectively, of a geometric progression whose common ratio is \(r\).
(i) Write down two equations connecting \(d\) and \(r\). Hence show that \(r = \frac{3}{4}\) and find the value of \(d\). [6]
(ii) Find the sum to infinity of the geometric progression. [2]
(iii) Find the sum of the first 8 terms of the arithmetic progression. [2]
The first term of a geometric progression is 81 and the fourth term is 24. Find
(i) the common ratio of the progression,
(ii) the sum to infinity of the progression.
The second and third terms of this geometric progression are the first and fourth terms respectively of an arithmetic progression.
(iii) Find the sum of the first ten terms of the arithmetic progression.
The 1st term of an arithmetic progression is \(a\) and the common difference is \(d\), where \(d \neq 0\).
(i) Write down expressions, in terms of \(a\) and \(d\), for the 5th term and the 15th term.
The 1st term, the 5th term and the 15th term of the arithmetic progression are the first three terms of a geometric progression.
(ii) Show that \(3a = 8d\).
(iii) Find the common ratio of the geometric progression.
The second term of a geometric progression is 3 and the sum to infinity is 12.
(i) Find the first term of the progression.
An arithmetic progression has the same first and second terms as the geometric progression.
(ii) Find the sum of the first 20 terms of the arithmetic progression.
A small trading company made a profit of $250,000 in the year 2000. The company considered two different plans, plan A and plan B, for increasing its profits.
Under plan A, the annual profit would increase each year by 5% of its value in the preceding year. Find, for plan A,
(i) the profit for the year 2008,
(ii) the total profit for the 10 years 2000 to 2009 inclusive.
Under plan B, the annual profit would increase each year by a constant amount $D$.
(iii) Find the value of $D$ for which the total profit for the 10 years 2000 to 2009 inclusive would be the same for both plans.
A geometric progression has 6 terms. The first term is 192 and the common ratio is 1.5. An arithmetic progression has 21 terms and common difference 1.5. Given that the sum of all the terms in the geometric progression is equal to the sum of all the terms in the arithmetic progression, find the first term and the last term of the arithmetic progression.
A progression has a first term of 12 and a fifth term of 18.
(i) Find the sum of the first 25 terms if the progression is arithmetic.
(ii) Find the 13th term if the progression is geometric.
The first term of a geometric progression and the first term of an arithmetic progression are both equal to \(a\).
The third term of the geometric progression is equal to the second term of the arithmetic progression.
The fifth term of the geometric progression is equal to the sixth term of the arithmetic progression.
Given that the terms are all positive and not all equal, find the sum of the first twenty terms of the arithmetic progression in terms of \(a\).
The first term of an arithmetic progression is \(a\) and the common difference is \(-4\). The first term of a geometric progression is \(5a\) and the common ratio is \(-\frac{1}{4}\). The sum to infinity of the geometric progression is equal to the sum of the first eight terms of the arithmetic progression.
(a) Find the value of \(a\).
The \(k\)th term of the arithmetic progression is zero.
(b) Find the value of \(k\).
The first, second and third terms of an arithmetic progression are \(a\), \(\frac{3}{2}a\) and \(b\) respectively, where \(a\) and \(b\) are positive constants. The first, second and third terms of a geometric progression are \(a\), 18 and \(b + 3\) respectively.
(a) Find the values of \(a\) and \(b\).
(b) Find the sum of the first 20 terms of the arithmetic progression.
Two heavyweight boxers decide that they would be more successful if they competed in a lower weight class. For each boxer this would require a total weight loss of 13 kg. At the end of week 1 they have each recorded a weight loss of 1 kg and they both find that in each of the following weeks their weight loss is slightly less than the week before.
Boxer Aโs weight loss in week 2 is 0.98 kg. It is given that his weekly weight loss follows an arithmetic progression.
Boxer Bโs weight loss in week 2 is 0.92 kg and it is given that his weekly weight loss follows a geometric progression.
Two schemes are proposed for increasing the amount of household waste that is recycled each week.
Scheme A is to increase the amount of waste recycled each month by 0.16 tonnes.
Scheme B is to increase the amount of waste recycled each month by 6% of the amount recycled in the previous month.
The proposal is to operate the scheme for a period of 24 months. The amount recycled in the first month is 2.5 tonnes.
For each scheme, find the total amount of waste that would be recycled over the 24-month period.
The first three terms of an arithmetic progression are 4, x and y respectively. The first three terms of a geometric progression are x, y and 18 respectively. It is given that both x and y are positive.
(i) Find the value of x and the value of y.
(ii) Find the fourth term of each progression.
On a certain day, the height of a young bamboo plant was found to be 40 cm. After exactly one day its height was found to be 41.2 cm. Two different models are used to predict its height exactly 60 days after it was first measured.
(i) Using model A, find the predicted height in cm of the bamboo plant exactly 60 days after it was first measured.
(ii) Using model B, find the predicted height in cm of the bamboo plant exactly 60 days after it was first measured.