### Commercial Mathematics

goals
On selling an article for $Rs-2,640$, profit of $10$ percent is made:
Find (i) cost price of the article.
Why do we need an index number?
Find the value of $9\%$ of $8400$ kg.
A man invests Rs. $46875$ at $4\%$ per annum compound interest for $3$ years.
A man invests Rs. $46875$ at $4\%$ per annum compound interest for $3$ years.