Question

Out of the total production of iron from hematite, an ore of iron, 20% of the ore gets wasted. Out of the remaining iron, only 25% is pure iron. If the pure iron obtained in a year from a mine of hematite was 80000 kg, then the quantity of hematite mined in the year is

• A. 400000 kg
• B. 500000 kg
• C. 450000 kg
• D. 600000 kg

Answer 1

The Correct Option is A

Let 100 kg of hematite be obtained then 20% of it get wasted that means 80 kg of ore remains.

Pure iron = 25\(\%\) of remaining ore = 80\(\times\frac{25}{100}\)
= 20 kg.
20 kg pure Iron is obtained from 100 of hematite.

1 kg pure Iron is obtained from = \(\frac{100}{20}\) hematite;

Then, 80000 kg pure Iron is obtained from = \((\frac{100}{20})\times80000\)
= 400000 kg hematite.
So the correct option is (A)