Starting with $8000$ workers,the company increases the number of workers by $5 \%$,$10 \%$,and $20 \%$ at the end of the first,second,and third year,respectively. The number of workers in the fourth year is:

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 $2002$?

An index of $12$ shares contains,among others,the shares of Vision Power,Vision Infra,and Vision Communication with weightage of $7\%$,$13\%$,and $15\%$ respectively. What is the increase in the prices of other shares,if these three rise by $9\%$,$10\%$,and $4\%$ respectively,while the index rises by $6\%$?

An engineering student has to secure $25 \%$ marks to pass. He gets $47$ marks and fails by $43$ marks. What are the maximum marks of the examination?

$A$ shopkeeper undertakes to supply $2000$ tables at $Rs. 1725$ each. He estimates that if $10\%$ are defective,which will be sold at $50\%$ of the original price,then the profit will be $15\%$ on his whole outlay. When the tables were supplied,$70\%$ of the tables were found defective. What loss did the shopkeeper incur?

$40 \%$ of $20 \% + 30 \%$ of $25 \% + 50 \%$ of $28 \%$ is equivalent to: