CAT 2003 Slot 2 — QA Question 23
Solving InequalitiesEasy
A real number x satisfying for every positive integer n, is best described by:
Answer & solution
Correct answer: 0 < x ≤ 4
- A
1 < x < 4
- B
1 < x ≤ 3
0 < x ≤ 4
- D
1 ≤ x ≤ 3
Solution
wher n is a positive integer
If n = 1, then 0 < x ≤ 4
As the value of n increases from 1 to infinity, the range of x approaches (1 < x ≤ 3).
So, the lower limit of x increases from almost 0 (to almost 1), while the higher limit decreases from 4 (to 3).
Thus, the lowest possible limit of x will be > 0 and the highest possible limit will be ≤ 4.
∴ For all range of n, 0 < x ≤ 4
Hence, option (c).