In each question two equations numbered (I) and (II) are given. You should…
2025
In each question two equations numbered (I) and (II) are given. You should solve both equations and mark the appropriate answer.
I. 2x2 – 9x + 10 = 0
II. y2 – 12y + 35 = 0
- A.
If x=y or no relation can be established
- B.
If x>y
- C.
If x<y
- D.
If x≥y
- E.
If x≤y
Attempted by 10 students.
Show answer & explanation
Correct answer: C
Concept
In a two-equation "quadratic comparison" problem, you first find the roots of each quadratic, then compare every x-root against every y-root. A single fixed relation (x>y, x<y, x≥y, x≤y, or x=y) holds only if the comparison is consistent across all root pairs; if different pairs give opposite relations, no relation can be established.
Application
Equation I: 2x2 – 9x + 10 = 0. Factor as (2x – 5)(x – 2) = 0, giving x = 5/2 = 2.5 or x = 2.
Equation II: y2 – 12y + 35 = 0. Factor as (y – 5)(y – 7) = 0, giving y = 5 or y = 7.
So x belongs to {2, 2.5} and y belongs to {5, 7}. The largest x-value is 2.5 and the smallest y-value is 5.
Since the largest x (2.5) is still smaller than the smallest y (5), every x-value is strictly less than every y-value.
Cross-check
Compare each pair: 2 < 5, 2 < 7, 2.5 < 5, 2.5 < 7 — all four comparisons give x smaller than y.
The relation is strict (the x-values never equal any y-value) and it never reverses, so the result is the strict less-than relation, not the "or equal" variant and not the no-relation case.
Therefore the established relationship is x < y.