Question 24

The ratio of copper to zinc in an alloy 'A' of 7kgs is 5:2. The ratio of the same metals in that order in another alloy 'B' of 7kgs is 3:4. If 28kg of alloy is made by mixing A and B in quantities x & y respectively so as to have the ratio of copper and zink in the ratio 1:1, then x : y is


Copper and Zinc ratio in A and B are 5:2 and 3:4.

According to question,


in x quantity of A copper and zinc are as following :

copper=(5x/7) and zinc =(2x/7).

in y quantity of B copper and zinc are as following :

copper=3y/7 and zinc=(4y/7).

So,total copper=(5x/7+3y/7)

and total zinc=(2x/7+4y/7).

According to question:



or,3x=y. Now put this value in (1).

4x=28 or, x=7.



D is correct choice.

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