Paper 1 · November 2010 · Groups
The set forms a group under addition modulo 3. State the identity element.
Model answer
0
Also accepted: e=0, zero
Explanation
Adding 0 to any of 0, 1 or 2 and taking the least non-negative remainder on division by 3 returns the same element, so 0 leaves every element unchanged and is the identity.
Derived from ZIMSEC Further Mathematics 9187/1, November 2010, Q5