If $A$'s salary is $40\%$ less than that of $B$,then how much percent is $B$'s salary more than that of $A$?

$A$ sum of $Rs$ $7,930$ is divided into $3$ parts and given on loan at $5 \%$ simple interest to $A, B$ and $C$ for $2, 3$ and $4$ years respectively. If the amounts (principal + interest) of all three are equal after their respective periods of loan,then the amount $A$ received as a loan is:

$34.5 \% \text{ of } 1800 + 12.4 \% \text{ of } 1500 = (?)^3 + 78$

In a History examination,the average for the entire class was $80$ marks. If $10 \%$ of the students scored $95$ marks and $20 \%$ scored $90$ marks,what was the average marks of the remaining students of the class?

In a college election between two candidates,one candidate got $55 \%$ of the total valid votes. $15 \%$ of the votes were invalid. If the total votes were $15,200$,what is the number of valid votes the other candidate got?

If $10 \%$ of $x$ is $3$ times $15 \%$ of $y,$ then find $x: y.$