Half of the volume of the milk and water mixture of ratio 7:5 is converted into a mixture of ratio 3:1 by the substitution(or replacement method) the mixture of ratio 7:5 was formed from the mixture 7:3 by adding the water in it. if 240 L milk is required in the replacement method ,what it the total amount of water was added t6o prepare the mixture 7:5 ? Select:
A) 100 L
B) 50 L
C) 400 L
D) 300 L
E) 200 L
2 actions have been done on the mix...   1)7:3 is converted into 7:5 mix..   2) half of the mix of 7:5 is converted in 3:1 by adding 240l milk..   let's start with 2 action as more info is given there..   let the mix common ratio be 2x..   so total sol = milk:water=7*2x:5*2x   240 l milk is added to half of it to make it 3:1..   so (7x+240)/5x =3:1..   we get x=30 or 2x=60..   so the sol is 7*60:5*60=420:300..   now we look at the first action ..   this was created from 7:3 mix...   so say x was added to get this ratio...   so 420/(300-x)=7/3..   here x =120..   but 120 does not seem to be a choice..   now why 120 has to be correct..   initial milk:water=420:180=7:3(this is given to us)..   120 l of water is added= 420:180+120=420:300=7:5(again this confirms with what has been given)   240 l of milk is removed from half the mixture..   half the mix=210:150..   add 240 l milk...   210+240:150=450:150=3:1(satisfies the given data in Q).   ANSWER:300 L
<result>D</result>
Half of the volume of the milk and water mixture of ratio 7:5 is converted into a mixture of ratio 3:1 by the substitution(or replacement method) the mixture of ratio 7:5 was formed from the mixture 7:3 by adding the water in it. if 240 L milk is required in the replacement method ,what it the total amount of water was added t6o prepare the mixture 7:5 ?