CAT 2025 Slot 1 QA Question 4

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CAT 2025 Slot 1QANumber Systems • Integral SolutionsModerate
The number of distinct pairs of integers (x,y)(x, y) satisfying the inequalities x>y≥3x > y \geq 3 and x+y<14x + y < 14 is
TITA Answer:
Answer and solution

Answer: 16

📌 Core Concept
To find the number of integer pairs (x,y)(x, y) satisfying x>y≥3x > y \geq 3 and $x + y < 14 , we systematically analyze each possible value of $ystartingfrom3anddeterminethecorrespondingvalidstarting from 3 and determine the corresponding validx$ values.
🔢 Step-by-Step Solution
1
Fix y=3y = 3:
x>3x > 3 implies x≥4x \geq 4.
x+3<14x + 3 < 14 implies x<11x < 11.
Possible xx values: 4, 5, 6, 7, 8, 9, 10.
Number of pairs:
7
2. Fix y=4y = 4:
x>4x > 4 implies x≥5x \geq 5.
x+4<14x + 4 < 14 implies x<10x < 10.
Possible xx values: 5, 6, 7, 8, 9.
Number of pairs:
5
3. Fix y=5y = 5:
x>5x > 5 implies x≥6x \geq 6.
x+5<14x + 5 < 14 implies x<9x < 9.
Possible xx values: 6, 7, 8.
Number of pairs:
3
4. Fix y=6y = 6:
x>6x > 6 implies x≥7x \geq 7.
x+6<14x + 6 < 14 implies x<8x < 8.
Possible xx value:
7
- Number of pairs:
1
5. For y≥7y \geq 7:
x>yx > y implies x≥y+1x \geq y + 1.
x+y<14x + y < 14 implies x<14−yx < 14 - y.
For y=7,xy = 7 , x must be

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