A shopkeeper bought fertilizers worth ₹ 8000 from the city and brought it to his village. He spent ₹ 520 on transportation. If he wants to make an overall profit of 20%, for how much should he sell the whole material?

Hint: To solve this question, we first need to find the cost incurred to the shopkeeper for the fertilizers he bought. This cost price will be the sum of the whole sale price of the fertilizers and extra cost of transportation from the city to the village. Once we are able to find the cost price, we will find the 20% of this cost price. The final selling price will be the sum of the cost price and profit percent of the cost price.

Complete step-by-step answer:
It is given to us that the shopkeeper bought fertilizers worth ₹ 8000 from the city to sell in the village.
This is the wholesale price of the fertilizers.
Then it is given that he had to pay ₹ 520 as the cost of transportation.
Thus, the total cost price of the fertilizers he bought will be the sum of its whole sale price and the cost of transportation.
$\begin{align}
  & \Rightarrow cp=8000+520 \\
 & \Rightarrow cp=8520 \\
\end{align}$
Therefore, the cost price incurred to the shopkeeper for the fertilizers.
It is given that the shopkeeper wants to earn a profit of 20%.
To find the selling price, such that the shopkeeper earns 20% of profit, we have to find 20% of the cost price.
Therefore, 20% of cost price, i.e. Rs 8520 is given as $\dfrac{20}{100}\times 8520=1704$
Hence, 20% of the cost price is ₹ 1720
The final selling price is the sum of the cost price and profit percent of cost price.
Hence, the selling price = ₹ 8520 + ₹ 1720 = ₹ 10224.
Therefore, the shopkeeper has to sell the fertilizers at ₹ 10224 to make a profit of 20%.

Note: Students should be well versed with concepts of percentage so that profit loss problems can be solved quickly. Students can also directly find various values by substituting known values in the relation $g=\dfrac{sp-cp}{cp}\times 100\%$, where g is the gain percentage, sp is the selling price and cp is the cost price.