Solution: Forget the conventional way to solve DS questions.We will solve this DS question using the variable approach.
The first step of the Variable Approach: The first step and the priority is to modify and recheck the original condition and the question to suit the type of information given in the condition.
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Learn the 3 steps. [Watch lessons on our website to master these 3 steps]
Step 1 of the Variable Approach: Modifying and rechecking the original condition and the question.
We have to find ‘Is 20% of n greater than 30% of the sum of n and \(\frac{1}{4}\)’?
=> 20% of n > 30% of (n + \(\frac{1}{4}\))
=> \(\frac{20}{100}\cdot n>\frac{30}{100}\cdot\left(n+\frac{1}{4}\right)\)
=> \(\frac{20n}{100}>\frac{30n}{100}+\frac{30}{100}\cdot4\)
=> \(\frac{n}{5}>\frac{3n}{10}+\frac{6}{5}\)
=> \(-\frac{6}{5}>\frac{3n}{10}-\frac{n}{5}\)
=> \(-\frac{6}{5}>\frac{3n-2n}{10}\)
=> \(-\frac{6}{5}>\frac{n}{10}\)
=> -12 > n
=> n < -12
We have to know ‘Is n < -12’?
Condition (1) tells us that 0 < n < 2.
=> n < -12
Since the answer is a unique NO, condition (1) alone is sufficient by CMT 1 which states that there should be a unique Yes or a NO.
Condition (2) tells us that n > 0.25.
=> n < -12
Since the answer is a unique NO, condition (1) alone is sufficient by CMT 1 which states that there should be a unique Yes or a NO.
Each condition alone is sufficient.
So, D is the correct answer.
Answer: D
