Question
A five digit number 2A78B, is divisible by 55. What is
the difference between the maximum and minimum possible value of (A+B)?Solution
Solution.
2A78B
2A78B is divisible by 55 Or 11×5.
So, divisibility rule of 11 and 5
a given number can only be completely divided by 11 if the difference of the sum of digits at odd position and sum of digits at even position in a number is 0 or 11 .
If the last number is either 0 or 5, the entire number is divisible by 5 .
Maximum possible value of A and B=6 and 5
Maximum possible value of A+B=6+5=11
Minimum value of A and B=1 and 0
Minimum value of (A+B) =1+0=1
Difference between the maximum and minimum possible value of (A+B)=11-1=10.
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