The difference of three-digit number

Question:

The difference of three-digit number and the number obtained by putting the digits in reverse order is always divisible by 9 and——-.

Solution:

11

Let abc be a three-digit number, then we have

abc -cba = (100a + 10b + c)- (100c + 10b+ a) ; = (100a – a) + (c – 10Cc)

= 99a – 99c = 99(a -c)

= 9 x 11 x (a – c)

Hence, abc – cba is always divisible by 9,11 and (a – c).

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