Which term of the sequence t_n = 5n − 3 for n ≥ 1 is 607?

Step-by-step solution

Idea: Put t_n = 607 and solve for the position n.

1. 5n − 3 = 607½ mark
2. 5n = 610 ⇒ n = 1221 mark
3. So 607 is the 122nd term.½ mark

Check: 5 × 122 − 3 = 610 − 3 = 607 ✓.

Answer to write in the exam

Common mistakes that cost marks

• Dividing 607 by 5 directly (121.4) without first adding 3.
• Answering ‘607th term’. 607 is the term; its position is 122.
• Writing 5n = 604 by subtracting 3 from 607.

How this can come in the exam

Try one yourself

Which term of t_n = 6n + 5 is 413?

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