Subject: General Aptitude · Chapter: Profit and Loss · Exam: 2009 · Marks: · Difficulty:
A man sells a book at a profit of $20 \%$. If he had bought it at 20\% less and sold it for ₹ 18 less, he would have gained 25\%. The cost price of the book is
(a)₹ 60
(b)₹ 70
(c)₹ 80
(d)₹ 90
Answer
Answer (as printed): D
Explanation
Let the C.P. be ₹ 100. Then, profit = 20\%. S.P. = ₹ 120. New C.P. $=20 \%$ less $=₹ 80$. If gain is $25 \%$ then S.P. $=₹\left(\frac{125}{100} \times 80\right)=₹ 100$. Difference in S.P. $=₹(120-100)=₹ 20$. If difference in S.P. is ₹ 20,. then C.P. $=₹ 100$. If difference in S.P. is ₹ 18, then C.P. $=₹\left(\frac{100}{20} \times 18\right)=₹ 90$.
Explanation as extracted from the printed page; notation may be imperfect.