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- Standard 13
- Quantitative Aptitude
Oil equal to $20 \%$ of the weight of ground nut is extracted in a mill. The matter left after extraction is sold as cattle feed at the rate of $Rs.\, 12.5$ per $kg$. The ground nuts are bought at $Rs.$ $20$ per $kg.$ the processing cost is $Rs.\, 5$ per $kg$. At what price $(Rs.$ per $kg$ ) should the oil be sold to earn $20 \%$ profit on total costs (Total cost $=$ cost of groundnuts and processing costs)?
$250$
$150$
$200$
$100$
Solution
Let the Total weight of the groundnut $=100$ $kgs$
Total cost $=100 \times(20+5)=$ $Rs.$ $2500$
Amount that should be received after $20 \%$ profit $=2500 \times 1.2=$ $Rs. 3000$
since $80 \%$ of the weight of groundnut is left and sold as cattle feed for $Rs.$ $12.5 / kg$
Amount received after selling the waste $=100 \times 0.8 \times 12.5=$ $Rs. 1000$
$\therefore$ Remaining amount to be received by selling oil $=3000-1000=$ $Rs. 2000$
since weight of oil $=100 \times 0.2=20$ litres
selling cost of oil $=2000 / 20=$ $Rs. 100$ per liter
