Suppose 1 z. Let « and f be the three-digit numbers given by a = xyz and B = zyx so that x, y, z are the digits as they are shown. Set y=a-f. How many of the following statements are always true? I. 2 does not divide y. Il. 3 divides y. Ill. 5 does not divide y. IV. 7 does… | UPSC CAPF 2026 Q No 69

Accepted Answer: (A) 3

Topic Covered: Quantitative Aptitude and Reasoning

Key Concept: Mathematical relationships, counting and logical analysis

The reversal subtraction simplifies to γ = 99(x − z). This immediately gives fixed divisibility properties, after which each listed divisibility statement can be tested.

The key is to apply the central fact, formula, definition or relationship tested in the question and then eliminate alternatives that do not satisfy it.