the average age of a class of 25 students is 26 years . the average increased by 1 when the teacher ' s age also included . what is the age of the teacher ?
"total age of all students = 25 ã — 26 total age of all students + age of the teacher = 26 ã — 27 age of the teacher = 27 ã — 26 â ˆ ’ 25 ã — 26 = 26 ( 27 â ˆ ’ 25 ) = 26 ã — 2 = 52 answer is c ."
subtract(multiply(add(25, 1), add(26, 1)), multiply(25, 26))