Question

Difference between a four digit number and its reverse is always divisible by.​

Answer 1

$\huge{\mathfrak{\underline{\underline{Answer:-}}}}$

The answer is 9.

$\huge{\mathfrak{\underline{\underline{Explanation:-}}}}$

Let four digit number be abcd

abcd can also be written in the form 1000a + 100b + 10c + d

Reverse of abcd is dcba which can be written as 1000d + 100c + 10b + a

So difference between them is (1000a + 100b + 10c + d) - (1000d + 100c + 10b + a)

( 999a + 90b - 90c - 999d) = 9( 111a + 10b - 10c - 111d )

So, difference is always divisible by 9.

Answer 2

Step-by-step explanation:

Answer refer in Attachment

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