If $A$'s salary is $30\%$ more than that of $B$,then by how much percent is $B$'s salary less than that of $A$ (in $\%$)?

$A$ man donates $30\%$ of his wealth to charity. He gives $30\%$ and $25\%$ of the remaining wealth to his wife and son respectively. The rest he divides equally between his three daughters. One of his daughters gets $Rs$ $42$ lakh as her share. What was the man's total wealth (in $Rs$ lakhs)?

In an examination,$70 \%$ of the candidates passed in English,$80 \%$ passed in Mathematics,and $10 \%$ failed in both subjects. If $144$ candidates passed in both,the total number of candidates was:

The price of cooking oil has increased by $25 \%$. The percentage of reduction that a family should effect in the use of cooking oil,so as not to increase the expenditure on this account,is (in $\%$)

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?

Suman's project report on 'Development with dignity',consists of $25$ pages,each with $60$ lines and $75$ characters per line. If the number of lines is reduced to $55$ but the number of characters per line is increased to $90$,what is the percentage change in the number of pages? (Assume the number of pages to be a whole number.)