An arithmetic sequence has a first term of 7 and a common difference of 4. What is its fifteenth term?

1. Each term of an arithmetic sequence is the first term plus a number of common differences. 2. Getting from the first term to the fifteenth term takes fourteen steps, not fifteen. 3. So the fifteenth term is 7 plus 14 multiplied by 4. 4. Fourteen multiplied by 4 is 56, and 56 plus 7 is 63. 5. The answer 67 is the trap for using fifteen steps instead of fourteen. _Source: Siyavula Mathematics Grade 12 (Everything Maths, CC BY 4.0), Chapter 1: Sequences and series_