The quantity of water needed to reduce $9 \ ml$ of shaving lotion containing $50 \%$ alcohol to a lotion containing $30 \%$ alcohol is: (in $ml$)

$270$ candidates appeared for an examination,of which $252$ passed. The pass percentage is (in $\%$)?

Suresh gave $40 \%$ of his income to his wife. He gave $25 \%$ of the remaining amount to his son. Of the remaining amount,he spent $60 \%$ on education. Now,the amount with him is $₹ 2700$. What is the amount he gave to his wife?

In an examination,$5 \%$ of the applicants were found ineligible and $85 \%$ of the eligible candidates belonged to the general category. If $4275$ eligible candidates belonged to other categories,then how many candidates applied for the examination?

The income of a company increases $20 \%$ per annum. If its income is $Rs$ $42664000$ in the year $1999$,what was its income in the year $1997$?

Shruti decided to donate $12 \%$ of her salary to an orphanage. On the day of donation,she changed her mind and donated $Rs. 3150$,which was $75 \%$ of what she had decided earlier. How much is Shruti's salary?