The strength of an indigo solution in percentage is equal to the amount of indigo in grams per 100 cc of water. Two 800 cc bottles are filled with indigo solutions of strengths 33% and 17%, respectively. A part of the solution from the first bottle is thrown away and replaced by an equal volume of the solution from the second bottle. If the strength of the indigo solution in the first bottle has now changed to 21% then the volume, in cc, of the solution left in the second bottle is:
Explanation
33% solution is mixed with 17% solution to get 21% solution. So, they must be mixed in the ratio
(21-17): (33-21) = 4:12 = 1:3
Since, total volume of the bottle is 800 cc, it implies that 200 cc of first bottle was mixed with 600 cc of the second bottle
Then, the solution left in the second bottle = 800 – 600 = 200 cc
Ans: 200