In a college library, four different business newspapers - Economic Times,…

In a college library, four different business newspapers - Economic Times, Business Standard, Business Line and Financial Express - are available. All students visit the library regularly, but 20% of them do not read any business newspaper. The four newspapers, in the order given above, are read by 230, 180, 180 and 220 students respectively. The number of students reading exactly 2 newspapers, for any pair of two newspapers, is 20. There are 30 students who read all four newspapers, but nobody reads exactly three out of the four newspapers.

What percentage of the people reading Business Standard also read at least one other newspaper?