Evaluate $28 \%$ of $450 + 45 \%$ of $280$.

If the numerator of a fraction is increased by $120 \%$ and the denominator is also increased by $350 \%$,then the fraction becomes $\frac{11}{27}$. What was the original fraction?

Amit's monthly income is $30 \%$ more than that of Raunaq. Raunaq's monthly income is $20 \%$ less than that of Deepak. If the difference between the monthly incomes of Amit and Deepak is ₹ $800$,what is the monthly income of Raunaq?

In an examination,$65 \%$ of students pass in History and $55 \%$ of students pass in Hindi. If $5 \%$ of students fail in both subjects,what is the percentage of students who passed in both subjects?

In a mixture of milk and water,the proportion of water by weight was $75 \%$. If $15 \text{ gm}$ of water is added to $60 \text{ gm}$ of this mixture,what will be the new percentage of water by weight (in $\%$)?

The tax on a commodity is diminished by $10 \%$ and its consumption increases by $10 \%$. Find the effect on revenue.