Which of the given arrangements is not the correct way of packing 20 pens?
Ram arranged 7 pens (4 blue & 3 red in color) in a way that no two pens of same color lie side by side. Which pattern does the arrangement follow?
Rohit bought 10 packs of pens, which had 5 pens in one pack for Rs. 10 per pack and while selling them he packed them in 5 different pack of 10 pens each and sold them at Rs. 40 per pack. Find the total profit.