Chinese Painters And Story Behind Them | BHUMIKA CHAUHAN | ENGLISH

Students of Saraswati Bhawan have pledged not to use Chinese items in future. During the survey, it is found that 44% of them use Chinese Headphones, 30% of them have Chinese Mobiles and 28% of them use Chinese Pen drives. 18% students have exactly two gadgets out of the three gadgets and 2% students have all three gadgets as mentioned above. If a student is randomly selected, then probability that the student does not use any Chinese gadget is

How many such pairs of letters are there in the word 'BRIGHTEN' each of which has as many letters between them as in the English alphabet ?