The population of a town increased from $1,75,000$ to $2,62,500$ in a decade. The average percent increase of population per year is?

$40 \%$ of $1640 + ? = 35 \%$ of $980 + 150 \%$ of $850$

The production of a company has ups and downs every year. The production increases for two consecutive years consistently by $15 \%$ and in the third year it decreases by $10 \%$. Again in the next two years it increases by $15 \%$ each year and decreases by $10 \%$ in the third year. If we start counting from the year $1998$,approximately what will be the effect on the production of the company in $2002$?

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

$A$ number,when $35$ is subtracted from it,reduces to its $80$ percent. What is four-fifths of that number?

$1200$ boys and $650$ girls appeared in an examination. If $70 \%$ of boys and $40 \%$ of girls failed,find the approximate percentage of passed students.