Question

Ravi purchased 30 kg of rice at the rate of Rs.17.50 per kg and another 30 kg rice at a certain rate. He mixed the two and sold the entire quantity at the rate of Rs.18.60 per kg and made an overall profit of 20%.
What was the price (per kg) of the second lot of rice?

• A. Rs.12.50
• B. Rs.13.50
• C. Rs.14.50
• D. Rs.15.50
• E. None of these

Answer 1

The correct option is B

Rs.13.50

Let the required price per kg be Rs.x.

Then, C.P. of 60 kg rice $=Rs.(30\times 17.50+30\times x)=Rs.(525+30x$)

S.P. of 60 kg rice $=Rs.(60\times 18.60)=Rs.1116$

$\therefore$ $\frac{1116-(525+30x)}{525+30x}\times 100=20\iff \frac{591-30x}{525+30x}=\frac{1}{5}$

$⟺2955-150x=525+30x$
$⟺180x=2430$
$⟺x=Rs.\frac{2430}{180}=\frac{27}{2}=Rs.13.50$

So, the C.P. of the second lot of rice is Rs.13.50 per kg.