Which of the following is true about the absolute difference between a...
Let the units digit and tens digit be 'a' and 'b' respectively.
The number = 10b + a
Required difference = |(10b + a) - (10a +b)|= |9b - 9a| = 9 x |b - a|
The difference will always be divisible by 9.
Hence, option 3.
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Which of the following is true about the absolute difference between a...
If I reverse 9 then its become absolute difference between a two- digit number. right ?
Which of the following is true about the absolute difference between a...
The absolute difference between a two-digit number and the number obtained by reversing its digits can be found by subtracting the two numbers. Let's consider a two-digit number AB, where A represents the tens digit and B represents the units digit.
To reverse the digits, we obtain the number BA. The absolute difference between AB and BA can be calculated as follows:
AB - BA = 10A + B - (10B + A) = 9A - 9B = 9(A - B)
From this expression, we can see that the absolute difference is always divisible by 9, regardless of the values of A and B. This means that option c) is true.
Explanation:
To understand why the absolute difference is always divisible by 9, let's consider a few examples:
1) If we take the number 23, its reverse is 32. The absolute difference is 23 - 32 = -9, which is divisible by 9.
2) If we take the number 78, its reverse is 87. The absolute difference is 78 - 87 = -9, which is again divisible by 9.
3) If we take the number 36, its reverse is 63. The absolute difference is 36 - 63 = -27, which is divisible by 9.
We can observe that the absolute difference is always a multiple of 9. This is because when we subtract the two numbers, we are effectively subtracting the sum of their digits. The difference will always be a multiple of 9 because the digits vary by a multiple of 9. For example, in the number 23, the difference between the tens digit (2) and the units digit (3) is 1, which is a multiple of 9.
In conclusion, the absolute difference between a two-digit number and the number obtained by reversing its digits is always divisible by 9.
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