On integers, (aRb) is defined when (a-b) is divisible by (6). Which is the equivalence class of (20)?

Correct answer: ({..., -4,2,8,14,20,26,...})

Step 1: Integers related to (20) must differ from (20) by a multiple of (6). Step 2: (20) gives remainder (2) on division by (6), so all integers with remainder (2) are in its class. Step 3: In modulo-class questions, first find the remainder of the given element.