Question

The relation R defined on the set of natural numbers as {(a, b) : a differs from b by 3}is given

• A. {(1, 4), (2, 5), (3, 6),.....}
• B. {(4, 1), (5, 2), (6, 3),.....}
• C. {(1, 3), (2, 6), (3, 9),.....}
• D. none of these

Answer 1

Answer: (B)

The set is {(a, b): a - b = 3, a, b $\in$ N}
Here a = b + 3
For b = 1, a = 4
For b = 2, a = 5
For b = 3, a = 6.
and so, on Hence the given set is {(4, 1), (5, 2), (6, 3)...}