Let the printed price of the article be $x$.

$\text{GST}=7\%\text{of}x=\left(\frac{7}{100}\right)\times x=\frac{7x}{100}$

$\text{Selling price}=x+\frac{7x}{100}=\frac{107x}{100}$

As per question, $\frac{107x}{100}=₹856$

$\Rightarrow x=\frac{856\times 100}{107}=₹800$

Hence, $\text{printed price}=₹800$

Discount = 30% of ₹ 800 $=\left(\frac{30}{100}\right)\times 800=₹240$

$\text{Cost price of the article}=800-240=₹560$

$\text{Overhead}=\text{cost of transportation}=₹40$

$\text{Actual cost price}=560+40=₹600$
GST is charged by the government on the sale of an item. It is collected by the shopkeeper from the customer and given to the government. Hence, while calculating profit we will not include GST amount.

$\text{Profit}=\text{Printed price}-\text{Actual cost price}=800-600=₹200.$

$\text{Profit \%}=\left(\frac{\text{profit}}{\text{cost price}}\right)\times 100=\left(\frac{200}{600}\right)\times 100$

$=\frac{100}{3}\%=33\frac{1}{3}\%$