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Future Year Question 001·Quants·Arithmetic·Percentages

Percentages — Future Year Question 001 | CAT Quantitative Aptitude

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Percentages — Future Year Question 001

Test your understanding of percentages, percentage increase and decrease, and algebraic constraints with this CAT-level Future Year Question from GRADSKOOL.

This question combines percentage change with integer conditions and requires careful interpretation of both relative and absolute changes.


Question

Two positive integers X and Y satisfy X + Y = 1000, with X a multiple of 25. X is increased by 20%, and Y is decreased by L% (where L is a positive multiple of 5, L ≤ 60), resulting in a combined total that is exactly 8% more than the original 1000.

Given that the actual amount by which Y decreases (in absolute terms) is exactly 60, find X.

A. 600

B. 800

C. 850

D. 700


Try It Yourself

Before watching the solution, try to solve the question using the information about the original total, the percentage increase in X, and the absolute decrease in Y.

Pay particular attention to the distinction between a percentage decrease and the actual amount of decrease.


Concept Tested

The primary concept tested is Percentages, specifically percentage increase and percentage decrease.

The question also involves:

  • Absolute versus percentage change
  • Algebraic representation of percentage changes
  • Integer constraints
  • Multiple conditions in a quantitative aptitude problem

This question belongs to:

Quantitative Aptitude → Arithmetic → Percentages


How to Approach This Question

Start by determining the new combined total after the overall 8% increase.

Then use the fact that the actual decrease in Y is given directly as 60.

Represent the 20% increase in X algebraically and combine it with the original relationship X + Y = 1000.

The key is to use the absolute decrease of 60 directly rather than unnecessarily solving for L first.

Once you obtain a candidate value for X, verify it against all the conditions given in the question.


CAT Preparation Insight

CAT questions involving percentages often include more information than is necessary for the most efficient solution.

A useful skill is identifying whether a percentage is being given as:

  • A relative change
  • An absolute change
  • A constraint that can be used for verification

In this question, the absolute decrease in Y is explicitly provided. Recognizing this can significantly simplify the setup.


Common Mistakes

  1. Treating the 8% increase as an 8% increase in X and Y individually.
  2. Using L directly as the numerical amount by which Y decreases.
  3. Ignoring the statement that the actual decrease in Y is exactly 60.
  4. Forgetting that X must be a multiple of 25.
  5. Failing to verify the obtained value against all the conditions.


Difficulty Level

Difficulty: Moderate

The calculations involved are not particularly complex, but the question contains multiple constraints that must be interpreted correctly. The main challenge is identifying the most useful information and setting up the percentage changes without unnecessary casework.


Video Solution

Have you solved it?

Watch the complete video solution for the step-by-step approach and final answer.

https://www.youtube.com/watch?v=LMEo5wsJobM


Related Topics

  • Percentage Increase and Decrease
  • Percentage Change
  • Successive Percentage Change
  • Ratio and Percentage
  • CAT Arithmetic
  • CAT Quantitative Aptitude


Frequently Asked Questions

Q. What concept is tested in this CAT Future Year Question?

The primary concept tested is Percentages, with emphasis on percentage increase, percentage decrease and absolute change.

Q. Which CAT section does this question belong to?

This question belongs to CAT Quantitative Aptitude, specifically the Arithmetic → Percentages area.

Q. What is the key idea needed to approach this question?

The key idea is to distinguish between the percentage decrease in Y and the actual amount by which Y decreases. The question directly provides the absolute decrease as 60.

Q. What difficulty level is this FYQ?

This is a Moderate difficulty CAT-level Future Year Question because it combines percentage calculations with multiple algebraic and integer constraints.

Q. Should I solve the question before watching the video?

Yes. Attempt the question independently first, then watch the complete video solution to compare your approach and reasoning.

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