CAT (QA) PYQs

Arun's present age in years is $40\%$ of Barun's. In another few years, Arun's age will be half of Barun's. By what percentage will Barun's age increase during this period?

A box has $450$ balls, each either white or black, there being as many metallic white balls as metallic black balls. If $40 \%$ of the white balls and $50 \%$ of the black balls are metallic, then the number of non-metallic balls in the box is

The income of Amala is $20 \%$ more than that of Bimala and $20 \%$ less than that of Kamala. If Kamala's income goes down by $4 \%$ and Bimala's goes up by $10 \%$, then the percentage by which Kamala's income would exceed Bimala's is nearest to