The price of an article was first increased by 10\% and then again by 20\%. If the last increased price be ₹ 33, the original price was (S.S.C., 2010)
(a)₹ 25
(b)₹ 26.50
(c)₹ 27.50
(d)₹ 30
Answer
Answer (as printed): A
Explanation
Let the original price be ₹ $x$. New final price $=120 \%$ of (110\% of ₹ $x$ ) $$=₹\left(\frac{120}{100} \times \frac{110}{100} \times x\right)=₹ \frac{132 x}{100} .$$ $\therefore \quad \frac{132 x}{100}=33 \Rightarrow x=\left(\frac{33 \times 100}{132}\right)=25$.
Explanation as extracted from the printed page; notation may be imperfect.