ABC26GN2262 · Percentage
Subject: General Aptitude · Chapter: Percentage · Exam: 2010 · Marks: · Difficulty:
A number reduced by 25\% becomes 225. What percent should it be increased so that it becomes 390?
(a)25\%
(b)30\%
(c)35\%
(d)45\%
Answer
Explanation
Let the number be $x$. Then, $$\begin{gathered} x-25 \% \text { of } x=225 \Rightarrow x-\frac{25}{100} x=225 \Rightarrow \frac{75 x}{100}=225 \\ \Rightarrow x=\left(\frac{225 \times 100}{75}\right)=300 . \end{gathered}$$ Required increase $=(390-300)=90$. ∴ Increase $\%=\left(\frac{90}{300} \times 100\right) \%=30 \%$.
Explanation as extracted from the printed page; notation may be imperfect.
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