in a class , 30 % of the students speaks truth , 20 % speaks lie and 10 % speaks both . if a student is selected at random , what is the probability that he has speak truth or lie ?
d ) 2 / 5
subtract(const_1, add(divide(10, multiply(multiply(const_5, const_5), const_4)), add(divide(30, multiply(multiply(const_5, const_5), const_4)), divide(20, multiply(multiply(const_5, const_5), const_4)))))