Rice is now being sold at $Rs. 30$ per $kg$. During last month,its rate was $Rs. 26$ per $kg$. Find by how much percentage must a family reduce its consumption to keep the expenditure fixed?

If the length and breadth of a rectangular field are increased,the area increases by $50 \%$. If the length is increased by $20 \%$,by what percentage was the breadth increased?

After giving a $25 \%$ discount on the entry ticket,the number of visitors increased by $30 \%$. What will be the impact on the total revenue from entry tickets compared to other days?

In a competitive examination in state $A$,$6\%$ of the total candidates who appeared were selected. State $B$ had an equal number of candidates who appeared,and $7\%$ of the candidates were selected,which resulted in $80$ more candidates being selected than in state $A$. What was the number of candidates who appeared from each state?

Two numbers $A$ and $B$ are such that the sum of $6\%$ of $A$ and $4\%$ of $B$ is two-thirds of the sum of $6\%$ of $A$ and $8\%$ of $B$. Find the ratio of $A:B$.

In an examination,$65 \%$ of students passed in Civics and $60 \%$ in History,while $40 \%$ passed in both of these subjects. If $90$ students failed in both History and Civics,then what is the total number of students?