A four digit number 4ab5 is divisible by 55. Then the value of b – a is


If a number is divisible by 55 than it must alsobe divisible by factors of 55 that is 5 and 11.

4ab5 is divisible by 11


By divisibility test of 11 difference of the sum of the alternate digits must be a multiple of 11.


(4 + b) – (a + 5) = 0,11,22…


4 + b – a – 5 = 0,11,22…


b – a -1 = 0,11,22…


b – a – 1 = 0 ( least value of b – a).


b – a = 1


Therefore option (b) is correct.

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