a Use Gauss elimination method to solve the following problem A shopkeeper is selling 3 types of fruits namely mango guava and pineapple By selling 3 kg of mangoes 1kg of guava and 2 pineapples he made a gain of 35 By selling 2 kg of mangoes 3kg of guavas and 1 pineapple he made a gain of 10 By selling 2 kg of guavas and 1 pineapple he made a loss of 5 How much profit or loss will he make if he sells 3 kg of mangoes and 2 pineapples b For which real values of a and b the matrix 20 bl becomes orthogonal