Question

divisibility tests of 11​

Answer 1

Answer:

Take the alternating sum of the digits in the number, read from left to right. If that is divisible by 11, so is the original number.

Step-by-step explanation:

for example, 2728 has alternating sum of digits 2-7+2-8 = -11. Since -11 is divisible by 11, so is 2728.