A man purchased 20 dozens of pencils at the rate of Rs. 240 per dozen. Two-thirds of the pencils were sold at the rate of Rs. 25 each and the rest of the pencils sold at Rs. 22 each. What is the average percentage of profit?

The total number of pencils bought is $$20\times\ 12=240$$ and the price of each pencil is $$\frac{240}{12}=20$$ rs. 
Therefore, the total money invested is 4,800

Now, 2/3 rd of the pencils i.e, $$\frac{2}{3}\times240=160\ $$ pencils are sold at rs 25, earning back $$160\times\ 25=4,000$$
The remaining 80 pencils are sold at rs 22, earning back $$80\times\ 22=1,760$$
Giving us a net revenue of Rs 5,760 and a net profit of Rs 960

The profit percentage is $$\frac{960}{4800}\times\ 100=20\%$$
Therefore, Option A is the correct answer.