the average of 9 numbers is 104 . average of the first 5 of them is 99 and that of the last 5 is 100 . find the 5 th number ?
sum of all the 9 numbers = 9 * 104 = 936 sum of the first 5 of them = 5 * 99 = 495 sum of the last 5 of them = 5 * 100 = 500 so , the 5 th number = 495 + 500 - 936 = 59 . answer : b
subtract(multiply(5, 100), subtract(multiply(9, 104), multiply(99, 5)))