The value of a machine is $Rs$ $6250$. It decreases by $10 \%$ during the first year,$20 \%$ during the second year,and $30 \%$ during the third year. What will be the value of the machine after $3$ years?

In an election between two candidates,one got $52 \%$ of the total valid votes. $25 \%$ of the total votes were invalid. The total number of votes were $8400$. How many valid votes did the other person get?

Two jars contain equal quantities of $40 \%$ alcohol. Swati changed the concentration of the first jar to $50 \%$ by adding extra quantity of pure alcohol. Sonali changed the concentration of the second jar to $50 \%$ by replacing a certain quantity of the solution with pure alcohol. By what percentage is the quantity of alcohol added by Swati more than that replaced by Sonali?

In an examination,$A$ got $25\%$ marks more than $B$,$B$ got $10\%$ less than $C$,and $C$ got $25\%$ more than $D$. If $D$ got $320$ marks out of $500$,the marks obtained by $A$ were:

The sum of two numbers is $2490$. If $6.5\%$ of one number is equal to $8.5\%$ of the other,then the numbers are:

Raman scored $456$ marks in an examination and Seeta got $54 \%$ marks in the same examination,which is $24$ marks less than Raman. If the minimum passing marks in the examination is $34 \%$,then how many more marks did Raman score than the minimum passing marks?