| Date | November 2010 | Marks available | 3 | Reference code | 10N.1.sl.TZ0.8 |
| Level | SL only | Paper | 1 | Time zone | TZ0 |
| Command term | Find | Question number | 8 | Adapted from | N/A |
Question
The first term of an arithmetic sequence is 3 and the sum of the first two terms is 11.
Write down the second term of this sequence.
Write down the common difference of this sequence.
Write down the fourth term of this sequence.
The nth term is the first term in this sequence which is greater than 1000. Find the value of n.
Markscheme
8 (A1) (C1)
[1 mark]
5 (A1)(ft) (C1)
[1 mark]
18 (A1)(ft) (C1)
[1 mark]
3 + 5 × (n – 1) > 1000 (M1)
Note: Allow equality sign and equal to 1001
n > 200.4 (A1)
Note: Accept n = 200.4 or 5n =1002
OR
(M1) for attempt at listing, (A1) for 998 and 1003 seen. (M1)(A1)
n = 201 (A1)(ft) (C3)
Note: Follow through from their answer to (b).
[3 marks]
Examiners report
Most candidates achieved at least the first three marks on this question and a significant number gained full marks. Up to five marks could be awarded even to students who did not find correctly the value of the nth term, but showed correct method and attempted to find the value of n. Some candidates lost the last mark for giving a non integer value.
Most candidates achieved at least the first three marks on this question and a significant number gained full marks. Up to five marks could be awarded even to students who did not find correctly the value of the nth term, but showed correct method and attempted to find the value of n. Some candidates lost the last mark for giving a non integer value.
Most candidates achieved at least the first three marks on this question and a significant number gained full marks. Up to five marks could be awarded even to students who did not find correctly the value of the nth term, but showed correct method and attempted to find the value of n. Some candidates lost the last mark for giving a non integer value.
Most candidates achieved at least the first three marks on this question and a significant number gained full marks. Up to five marks could be awarded even to students who did not find correctly the value of the nth term, but showed correct method and attempted to find the value of n. Some candidates lost the last mark for giving a non integer value.
