Question

A petrol pump owner mixed leaded and unleaded petrol in such a way that the mixture contains 10% unleaded petrol. What quantity of leaded petrol should be added to 1 litre mixture, so that the percentage of unleaded petrol becomes 5%?

• A. 1000 ml
• B. 900 ml
• C. 1900 ml
• D. 1800 ml

Answer 1

The correct option is A 1000 ml

Here, we have to find out the quantity of leaded petrol. Hence, we have to make certain changes in the given data.
% of leaded petrol in the mixture =100-10=90%
After addition of leaded petrol (that has to be calculated),
Percentage of leaded petrol becomes (100-5)=95%.
The required answer $=\left(\frac{95-90}{100-95}\right)$1000 ml =1000 ml.