5 kg material has been bought with 35% cream and 65% bread
=> Amount of cream = 35% of 5 kg = 1.75 Kgs
=> Amount of bread = 65% of 5 kg = 3.25 Kgs (Another way would be 5-1.75 = 3.25Kgs)

Now we want to convert the ratio from 35%-65% to 25%-75% by buying more bread.
Here the amount of cream remains constant, hence 1.75kgs of cream should be 25% of the total amount.
Hence we need to have 75% of the bread. Now 75% is 3 times 25%, therefore the amount of bread we should have is 3 times the amount of cream

=> 3*1.75 = 5.25 kgs of bread is required

We have 3.25 kgs of bread and hence require 2 extra kgs of bread.

Hence A is the correct answer.
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5kg has 35% cream or say ; 5*35/100 ; 7/4
and bread 5*65/100 ; 13/4

perfect cake ratio ; 25:75 ; 1:3
so 3*7/4 ; 21/4
kg of bread required ; 21/4-13/4 ; 8/4 ; 2kgs
IMO A
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