Question

Half of the volume of petrol and kerosene mixture of ratio 7:5 is converted into a mixture of ratio 3:1 by the replacement method. While the mixture of ratio 7:5 was formed from the mixture of 7:3 by adding the kerosene in it . If 240 ltr petrol is required in the replacement method, what is the total amount of kerosene was added to prepare the mixture of 7:5 ?

Answer 1

Answer:

total amount of kerosene was added to prepare the mixture of 7:5 = 200 ltrs

Explanation:  

For the first half mixture -->

=> 7P+K/12P = 3/4  

=> K = 2P

Given, K = 240 litres.

Hence, P = 120 litres.

Total half volume = 360 litres.

For the second half mixture -->

7:3 ratio => 252 litres Petrol and 108 litres Kerosene.

=> $\frac{252}{108+x}$ = $\frac{7}{5}$

=> 7x = 1400

Thus, x = 200 litres

total amount of kerosene was added to prepare the mixture of 7:5 = 200 ltrs