A five digit number 2A78B, is divisible by 55. What is the difference between the maximum and minimum possible value of (A+B)?
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.
In each of the following giving number series, a wrong number is given. Find out the wrong number?
3023, 3132, 3246, 3356, 3471
72, 80, 89, 153, 180, 394
7 12 33 126 635
23, 36, 75, 140, 233, 348
4, 8, 24, 96, 485, 2880, 20160
150, 900, 300, 1800, 600, 3700, 1200
In each of the following giving number series, a wrong number is given. Find out the wrong number?
46 23 23 34.5 70 172.5
...256 768 96 288 35 108
8 10 36 216 2592 62208
186, 179, 170, 162, 146, 131, 114