CAT (QA) PYQs

In an examination, the maximum possible score is $N$ while the pass mark is $45\%$ of $N$. A candidate obtains $36$ marks, but falls short of the pass mark by $68\%$. Which one of the following is then correct?

In an examination, the score of $A$ was $10\%$ less than that of $B$, the score of $B$ was $25\%$ more than that of $C$, and the score of $C$ was $20\%$ less than that of $D$. If A scored $72$, then the score of $D$ was

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