WBCS Mains 2019 Official Paper-VI

The ratio of bus and train fares from Burdwan to a certain place is $3:4$. If the train fare increases by $20\%$ and bus fare by $10\%$, then what will be the new ratio of bus and train fares?

When the price of rice increases by $12\frac{1}{2}\%$, a man can get $250\text{gm}$ less rice for $\text{Rs. }18$. Find the present cost of rice per kg.

Of four numbers, the second number is $20\%$ more than the first, the third is $10\%$ less than the second and the fourth number is $50\%$ more than the third. If the fourth number is $405$, find all the numbers.

The expenses for rice, fish and oil of a family are in the ratio $12:17:3$. The prices of these articles are increased by $20\%$, $30\%$ and $50\%$ respectively. By what percent will the total expenses for these articles of the family be increased?

In a certain examination, a candidate answered $25$ questions and two-fifth of the rest of the total number of questions, and he found that he has answered only $60\%$ of the total number of questions. How many questions did he answer?