Subject: General Aptitude · Chapter: Number System · Exam: · Marks: · Difficulty:
If x – y = 8, then which of the following must be true? I. Both x and y are positive. II. If x is positive, y must be positive. III. If x is negative, y must be negative.
(a)I only
(b)II only
(c)I and II
(d)III only
Answer
Answer (as printed): D
Explanation
It is given that x – y = 8. I. We may have x = 5 and y = – 3. So, it is not necessary that both x and y are positive. II. If x is positive, then it is not necessary that y is positive, as x = 5 ⇒ y = – 3. III. If x < 0, then y = x – 8 which is clearly less than 0. So, if x is negative, then y must be negative.
Explanation as extracted from the printed page; notation may be imperfect.