50% of the people in an area read Ittefaq and 60% of the people in that area read Prothom Alo. 20% people read both the newspapers. What percent of people do not read any of the newspapers?

প্রশ্নঃ 50% of the people in an area read Ittefaq and 60% of the people in that area read Prothom Alo. 20% people read both the newspapers. What percent of people do not read any of the newspapers?