Arithmetic & Geometric Series (Edexcel IGCSE Further Pure Maths): Exam Questions

Exam code: 4PM1

2 hours13 questions
1a
1 mark

The sum S subscript n of the first n terms of an arithmetic series is given by S subscript n space equals space 2 n left parenthesis n space plus space 3 right parenthesis

Find the first term of the series.

1b
2 marks

Find the common difference of the series.

1c
6 marks

The nth term of the series is space T subscript n

Given that 6 S subscript open parentheses n minus 4 close parentheses end subscript space equals space 7 T subscript open parentheses n plus 3 close parentheses end subscript find the value of n.

2
5 marks

The nth term of a geometric series is 3 straight e to the power of open parentheses 1 – 2 n close parentheses end exponent

Find the sum to infinity of this series.

Give your answer in the form fraction numerator a straight e over denominator straight e to the power of b space minus space 1 end fraction where space a spaceand b are integers to be found.

3a
4 marks

Expand fraction numerator 3 over denominator square root of 1 minus 2 x end root end fraction in ascending powers of x up to and including the term in x cubed

and simplifying each term as far as possible.

3b
1 mark

Write down the range of values of x for which this expansion is valid.

3c
3 marks

Hence, using your expansion with a suitable value for x, obtain an approximation to 5 decimal places of fraction numerator 1 over denominator square root of 10 space minus space 3 end fraction

4a
3 marks

Show that sum from r equals 1 to n of open parentheses 5 r minus 3 close parentheses space equals space n over 2 open parentheses 5 n minus 1 close parentheses

4b
2 marks

Hence, or otherwise, evaluate sum from r equals 31 to 60 of open parentheses 5 r minus 3 close parentheses

5a
4 marks

The sum of the first and second terms of a geometric series G is 400

The sum of the second and third terms of G is 100

Show that the common ratio of G is 1 fourth

5b
2 marks

Show that the first term of space G is 320

5c
2 marks

Find the sum to infinity of G

5d
4 marks

The sum to n terms of G is S subscript n

Find, using logarithms, the least value of n such that

S subscript n space greater than space 426.6

6a
5 marks

The sum of the fifth, sixth and seventh terms of an arithmetic seriesspace A is nine times the sum of the first and second terms.
The third term ofspace A is 12

Find the first term and common difference of space A

6b
4 marks

The nth term of space A is u subscript n

Find the value of sum from r equals 15 to 60 of u subscript r

6c
4 marks

The sum to n terms of A is S subscript n

Given that 2 S subscript n space minus space 5 u subscript n space equals space 10

find the value of n

7a
3 marks

A geometric series G has first term a and common ratio r
The third term of G is 9 and the sum to infinity of G is 192

Show that 64 r cubed minus 64 r squared plus 3 equals 0

7b
1 mark

A geometric series G has first term a and common ratio r
The third term of G is 9 and the sum to infinity of G is 192

Given that r is a rational number

write down the value of r

7c
2 marks

A geometric series G has first term a and common ratio r
The third term of G is 9 and the sum to infinity of G is 192

show that a =144

7d
4 marks

The sum to n terms of G is S subscript n

Using logarithms, find the least value of n such that S subscript n greater than 191.9

8a
3 marks

Show that sum from r equals 1 to n of left parenthesis 3 r plus 2 right parenthesis equals n over 2 left parenthesis 3 n plus 7 right parenthesis

8b
2 marks

Hence, or otherwise, evaluate sum from r equals 10 to 40 of left parenthesis 3 r plus 2 right parenthesis

9
6 marks

The nth term of a convergent geometric series is 8 to the power of left parenthesis 1 minus 2 n right parenthesis end exponent

Find the sum to infinity of the series.

Give your answer in the form p over qwhere p and q are integers to be found.

10a
2 marks

A geometric series G with common ratio r, has first term 16 and third term 2704 over 625

Find the two possible values of r

10b
2 marks

Given that r greater than 0

find the sum to infinity of G

10c
2 marks

The sum to n terms of G is greater than 33

Find, using logarithms, the least possible value of n
Show your working clearly.

11a
6 marks

The sum to n terms of an arithmetic series A is S subscript n

The sum of the first four terms of Ais 42 and the fifth term of Ais 23

Show that S subscript n equals sum from r equals 1 to n of left parenthesis P r minus Q right parenthesis where P and Q are prime numbers.

11b
4 marks

S subscript 2 n end subscript minus 3 U subscript n equals 1062 where U subscript n is the nth term of A

Find the value of n

12
4 marks

The nth term of an arithmetic series is a subscript n where

a subscript 10 plus a subscript 11 plus a subscript 12 equals 129 and a subscript 19 plus a subscript 20 plus a subscript 21 equals 237

Find a subscript 1

13a
5 marks

The n th term of a geometric series G is U subscript n

The first three terms of G are given by

U subscript 1 equals q left parenthesis 4 p plus 1 right parenthesis      U subscript 2 equals q left parenthesis 2 p plus 3 right parenthesis      U subscript 3 equals q left parenthesis 2 p minus 3 right parenthesis

Find the possible values of p

13b
3 marks

Given that G is convergent with sum to infinity 250

find the value of q