Question

Using divisibility rules, determine which of the following numbers are divisible by 11.

(i) 6446
(ii) 10934
(iii) 7138965
(iv) 726352​

Answer 1

Answer:

i) 6446

If the difference between the sum of the digits at odd places and the sum of the digits at even places of a number is either 0 or a multiple of 11. Then the number is divisible by 11.

Sum of the digits at odd places = 6 + 4 = 10

Sum of the digits at even places = 4 + 6 = 10

Difference 10 – 10 = 0

So, 6446 is divisible by 11.

ii) 10934

Sum of the digits at odd places = 4 + 9 + 1 = 14

Sum of the digits at even places = 3 + 0 = 3

Difference = 14 – 3 = 11

is a 11 multiple by divisibility rule for 11.

So, 10934 is divisible by 11.

iii) 7138965

Sum of the digits at odd places = 5 + 9 + 3 + 7 = 24

Sum of the digits at even places = 6 + 8 + 1 = 15

Difference = 24 – 15 = 9

is not a multiple by divisibility rule for 11So, 7138965 is not divisible by 11.

iv)726352

Sum of the digits at odd places = 2 + 3 + 2 = 7

Sum of the digits at even places = 5 + 6 + 7 = 18

Difference = 18 – 7 = 11

is a 11 multiple by divisibility rule for 11.

So, 726352 is divisible by 11.

Hope this helps you...