Option 3 : ± 3

**Given:**

A3BC and DE2F are four-digit numbers where each letter represents a different digit greater than 3.

Sum of two numbers = 15902

**Concepts used:**

Possible values of A, B, C, D, E and F = 4, 5, 6, 7, 8 and 9

**Calculation:**

As sum of two numbers is 15902 with unit place as 2,

⇒ C + F = 12 ----(1)

⇒ C = 4 or 8, F = 4 or 8

As ten’s place of sum is 0,

⇒ B + 2 + 1 = 10

⇒ B = 7

As hundred’s place of sum is 9,

⇒ E + 3 + 1 = 9

⇒ E = 5

As sum of thousand’s place of both numbers make 15,

⇒ A + D = 15

⇒ A = 6 or 9, D = 6 or 9

Difference between A and D = (6 – 9) or (9 -6) = ± 3

**∴**** Difference between A and D is ± 3.**