Using divisibility tests, determine which of the following numbers are divisible by 11: (a) 5445
A number is divisible by 11 if the difference between the sum of the digits at odd places and the sum of the digits at even places is divisible by 11. Difference = 9 – 9 = 0, which is divisible by 11. Therefore, the number 5445 is divisible by 11.
