If $P \%$ of $P$ is $36,$ then $P$ is equal to

The population of Delhi two years ago was $55000$. It increased by $12 \%$ in the first year and decreased by $15 \%$ in the second year. What was the population of the town at the end of $2$ years?

Two numbers are respectively $60 \%$ and $20 \%$ more than a third number. The second number expressed as a percentage of the first is:

$23 \%$ of $8040 + 42 \%$ of $545 = ? \%$ of $3000$

$A$ batsman scored $110$ runs which included $3$ boundaries and $8$ sixes. What per cent of his total score did he make by running between the wickets?

Sweta invested $Rs. 10,000$ in a scheme exactly three years ago. The value of the investment increased by $10\%$ during the first year,increased by $5\%$ during the second year,and decreased by $10\%$ during the third year. What is the value of the investment today?