Question

In a mixture of 100 liters of fuel, the ratio of petrol and adulterated particles is 4:1. if pump owner wants to the ratio to be 19:1, what would be the quantity of pure petrol to be added to the mixture?

Answer 1

It is very easy it will be 95 litre

Answer 2

Answer: 300 liters of pure petrol should be added.

Explanation: We are given the ratio of petrol and adulterated particles as

Petrol : Adulterated particles = 4 : 1  in 100 L of fuel.

Amount of petrol = $\frac{4\times 100}{4+1}=\frac{400}{5}=80L$

Amount of Adulterated petrol = $\frac{1\times 100}{4+1}=\frac{100}{5}=20L$

Now, let us assume that the amount of petrol to be added in order to have the ratio of 19 : 1 be x.

So, amount of petrol becomes = (80 + x) L

Amount of Adulterated petrol = 20 L

Now, the ratio becomes = (80 + x) : 20

Equation becomes:

$\frac{(80+x)}{20}=\frac{19}{1}$

Solving for x, we get

x = 300

Hence, 300 L of pure petrol must be added in order to make the ratio 19 : 1