the average age of 30 students in a class is 10 years . if teacher ' s age is also included then average increases 1 year then find the teacher ' s age ?
"total age of 50 students = 30 * 10 = 300 total age of 51 persons = 31 * 11 = 341 age of teacher = 341 - 300 = 41 years answer is d"
subtract(add(add(multiply(30, 10), 1), 30), multiply(30, 10))