A number when divided by a divisor leaves remainder of 24. When twice the original number is divided by the same divisor, the remainder is 11. What is the value of the divisor?

Let the number be N.
Therefore N = 5k + 3

On squaring both sides, we get
N² = ( 5k + 3)²
= 5( 5k² + 6k +1 ) + 4
? On dividing x² by 5, the remainder is 4

Let the given number be N
Therefore N = 357k + 39
Then,
357 k + 39 = ( 17 x 21k ) + ( 17 x 2 ) + 5
? Required remainder = 5

Let the number be N
According to question
N = 56k + 29
Then,
N = ( 8 x 7k ) + ( 8 x 3 ) + 5
Therefore if N will be divided by 8 the required remainder will = 5

Unit digit in 3⁴ = 1
? Unit digit in ( 3⁴ )¹⁶ = 1
? Unit digit in 3⁶⁵ = 3
Unit digit in 6⁵⁹ = 6
Unit digit in 7⁷¹ = 3

? Required unit digit = Unit digit in ( 3 x 6 x 3 )
= Unit digit in 54
= 4

Required unique digit = Unique digit in (7)⁷⁵⁴
= Unique digit in { (7⁴)¹⁸⁸ x 7² }
= Unique digit in ( 1 x 49 ) = 9

We know that, a number is divisible by 11 when the sum of the difference between the sum of its digit at even places and sum of its digit at odd places is either 0 or the difference is divisible by 11.

So number is 58129745812974
Sum of digit at odd places = 4 + 9 + 1 + 5 + 7 + 2 + 8 = 36
Sum of digit at even places = 7 + 2 + 8 + 4 + 9 + 1 + 5 = 36
So, required difference = 36 - 36 = 0
? number is divisible by 11.

Number between 0 and 11 which are multiple of 2 or 3
= 11/2 + 11/3 - 11/6 = 5 + 3 - 1
= 7

Number between 0 and -11 which are multiple of 2 or 3
= 11/2 + 11/3 - 11/6 = 5 + 3 - 1
= 7

? Number be 15, including 0

We know that, a number is divisible by 11 when the sum of the difference between the sum of its digit at even places and sum of its digit at odd places is either 0 or the difference is divisible by 11.

For 93455120
Sum of even places = 3 + 5 + 1 + 0 = 9
Sum of odd places = 9 + 4 + 5 + 2 = 20

There difference = 20 - 9 = 11
which is divisible by 11 so 93455120 is divisible by 11.

We know that, ( x^m - a^m ) is divisible by ( x + a ), for even value of m.
? 17²⁰⁰ - 1²⁰⁰ is divisible by 17 +1
? 17²⁰⁰ - 1 is divisible by 18.

Hence when 17²⁰⁰ divided by 18 the remainder is 1.

Remainder of 4¹⁰⁰⁰/7 = (4²)⁵⁰⁰/7 = (16)⁵⁰⁰/7
= 2⁵⁰⁰/7
= Remainder of 4 x 8¹⁶⁶/7
= 4