In a survey conducted on students studying in grade 10 at Adarsha Secondary School is determine suitable place for educational trips among Pokhara, Lumbini and Chitwan, it was found that 80 students considered Pokhara to be suitable, 60 students considered Lumbini to be suitable, and 90 students considered Chitwan to be suitable. While 30 students of that grade said that all three places are suitable, 10 students did not express any opinion and no one likes only two places.

A. If P,L and C denote the set of students who prefer pokhara,Lumbini and chitwan respectively, write the cardinality notation of students for whom all places are suitable.

B. Show the above information in a Venn diagram.

C. How many students are studying in grade 10 in the Adarsha Secondary School? Calculate it.

D. If 10 students,who did not express their opinion in the survey had said Lumbini as a suitable place,then what would have been the ratio of students who considered only pokhara was suitable place and only Lumbini was the suitable place?​