the average age of 60 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 = 60 * 10 = 600 total age of 51 persons = 61 * 11 = 671 age of teacher = 671 - 600 = 71 years answer is a"
subtract(add(add(multiply(60, 10), 1), 60), multiply(60, 10))