Question

400 pens in a shop. 40% are black, 20% are blue, 10% are yellow. If the remaining pens are red, how do I find the percentage of red pens?

Answer 1

30 percent are red pens

Explanation:

40 percent plus 20 percent plus 10 percent is 70 percent. That means 70 percent of the pens in the shop are not red and the other 30 percent are. If you want to know the exact amount do 30 percent of 400 which is 400 divided by 3.33 which is approximatly 120.