UPSC Prelims 2024·CSAT·Quantitative Aptitude·Algebra

When 70% of a number x is added to another number y, the sum becomes 165% of the value of y. When 60% of the number x is added to another number z, then the sum becomes 165% of the value of z. which one of the following is correct?

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Last updated 8 Jul 2026, 4:39 pm IST
  1. Az < x < yCorrect
  2. Bx < y < z
  3. Cy < x < z
  4. Dz < y < x

Explanation

Let's break down the problem into two statements:

Statement 1: "When 70% of a number x is added to another number y, the sum becomes 165% of the value of y." This can be written as: 0.7x + y = 1.65y Subtract y from both sides: 0.7x = 1.65y - y 0.7x = 0.65y To compare x and y, we can write x = (0.65 / 0.7)y = (65 / 70)y = (13 / 14)y. Since 13/14 is less than 1, it implies that x is less than y (x z).

Combining the two findings: From Statement 1: x z (which means z < x)

Putting these together, we get z < x < y.

Now let's check the options: A) z < x < y - This matches our derived relationship. B) x < y < z - Incorrect. C) y < x < z - Incorrect. D) z < y < x - Incorrect.

Therefore, option A is correct.

The final answer is A.

Quantitative Aptitude: When 70% of a number x is added to another number y, the sum becomes 165% of the value of y. When 60% of the number x is

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