Question

utest the divisibility of the following number by 11
1.3773
2.2230908​

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