An article costs $700$ to the manufacturer. He sells it to the retailer at a profit of $20\%$. The retailer marks the price $40 \%$ above the price he paid to the manufacturer. Later, he allows a discount of $10\%$ on the MP. Find the amount paid by the customer for the article to the retailer.

Find Simple interest for the following:

$68000$ at $16\frac{2}{3}\%$ per annum for $3$ years.

Find Simple interest for the following:

$3000$ at $18\%$ per annum for $\frac{3}{2}$ years.

Find Simple interest for the following:

$155000$ at $6\%$ per annum for $5$ years.

Find Simple interest for the following:

$6250$ at $4\%$ per annum for $36$ months.