Date | May Example question | Marks available | 2 | Reference code | EXM.2.AHL.TZ0.7 |
Level | Additional Higher Level | Paper | Paper 2 | Time zone | Time zone 0 |
Command term | Find | Question number | 7 | Adapted from | N/A |
Question
Let Sn be the sum of the first n terms of the arithmetic series 2 + 4 + 6 + ….
Let M = (1201).
It may now be assumed that Mn = (12n01), for n ≥ 4. The sum Tn is defined by
Tn = M1 + M2 + M3 + ... + Mn.
Find S4.
Find S100.
Find M2.
Show that M3 = (1601).
Write down M4.
Find T4.
Using your results from part (a) (ii), find T100.
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
S4 = 20 A1 N1
[1 mark]
u1 = 2, d = 2 (A1)
Attempting to use formula for Sn M1
S100 = 10100 A1 N2
[3 marks]
M2 = (1401) A2 N2
[2 marks]
For writing M3 as M2 × M or M × M2 (or(1201)(1401)) M1
M3 = (1+04+20+00+1) A2
M3 = (1601) AG N0
[3 marks]
M4 = (1801) A1 N1
[1 mark]
T4 = (1201)+(1401)+(1601)+(1801) (M1)
= (42004) A1A1 N3
[3 marks]
T100 = (1201)+(1401)+…+(120001) (M1)
=(100101000100) A1A1 N3
[3 marks]