CBSE Class 10 Answered

Let X and Y be the amounts of the two solutions respectively to be mixed.

Now the total acid amount in mixed should be same as total of that coming from individual solutions.

Hence,

0.5X + 0.25Y =  0.4(10) = 4    ... (1) 

Similarly the total water amount in the mixed solution should also balanced with the total of water amounts from individual solutions.

First solution is 50% acid so remainin 50% is water.

0.5X + 0.75Y = 0.6(10) = 6   .... (2)

Solving the two equations,

Y = 4 lit, and hence X = 10-4 = 6 lit.

Hence 6 lit of 50% and 4 lit of 25% acid solutions to be mixed.

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