Exam-style question
Try this first
A student records the ordered set {"N", "O", "P", "Q", "R"} as follows: "N" is 1st, "O" is 2nd, "P" is 4th, "Q" is 3rd, and "R" is 5th. Identify the error, give the correct ordinal positions, and explain why the correction is needed.
Model answer
What a good answer should say
- The error is that the positions of "P" and "Q" have been exchanged.
- The correct positions are "N" 1st, "O" 2nd, "P" 3rd, "Q" 4th, and "R" 5th.
- The positions must follow the order of the objects in the set, so the third object is "P" and the fourth object is "Q".
Explanation
Why this works
Ordinal numbers must match the numerical positions of objects in their stated order. Counting from the beginning of the set shows that "P" comes third and "Q" comes fourth.
Common mistake
No common mistake is linked to this question yet.