A merchant has 300 pumpkins. The merchant sells two-third of the pumpkins at the marked price, 75% of the remaining pumpkins at 20% reduced price, and finally the remaining pumpkins at 40% off the marked price. If the total sell price of pumpkins is Rs. 2750, then the original selling price of each pumpkin is

Let's take the original marked price to be MP.
2/3rd of the original 300 pumpkins were sold at the marked price, so the sales from this part is 200 MP.
75% of the remaining 100 pumpkins, which is 75 pumpkins were sold at a 20% discount, the sales from this part would be
 $$75\times\ \frac{4}{5}MP\ =\ 60MP$$
The remaining 25 pumpkins are sold at 40% discount, the sales from this part would be $$25\times\ \frac{3}{5}MP=15MP$$.

This gives us a total sales of $$200MP+60MP+15MP=275MP$$
We are given that this is equal to 2750, which gives us the value of MP to be 10.

Thus, Option B is the correct answer.