Subject: General Aptitude · Chapter: Profit and Loss · Exam: · Marks: · Difficulty:
A person purchases 90 clocks and sells 40 clocks at a gain of $10 \%$ and 50 clocks at a gain of $20 \%$. If he sold all of them at a uniform profit of 15\%, then he would have got ₹ 40 less. The cost price of each clock is
(a)₹ 50
(b)₹ 60
(c)₹ 80
(d)₹ 90
Answer
Answer (as printed): C
Explanation
Let C.P. of each clock be ₹ $x$. Then, C.P. of 90 clocks $=₹ 90 x$. $$\begin{aligned} & \therefore[(110 \% \text { of } 40 x)+(120 \% \text { of } 50 x)]-(115 \% \text { of } 90 x)=40 \\ & \Rightarrow 44 x+60 x-103.5 x=40 \Rightarrow 0.5 x=40 \Rightarrow x=80 . \end{aligned}$$
Explanation as extracted from the printed page; notation may be imperfect.