Answer is 14:
In worst case it will take 14 egg drops to find the value of N.

This follows the below logic.
Say, the egg breaks at floor n we try to find out by going (N-1) till the first floor by doing linear search.
Say for example, I throw the egg from 10th floor, and it breaks, I wíll go to floor 1 to 9 to find out the floor..
Then I would try the same logic for every 10 floors thereby setting a worst case scenario of 19 chances.. I.e. 10,20,30,40,50,60,70,80,90,100,91,92,93,94,95,96,97,98,99

To find optimum solution, let’s try this:
If for every n, egg doesnt break, instead of going to next n, go to N-1, this would save us one drop as we are doing a linear search with second egg when egg1 breaks…
So the series would look something like this..
N + (N-1) + (N-2) + (N-3) +…+ 1

Now this is a series which is equal to N(N+1)/2

Now since it is given that the egg may or may not break from 100th floor..

We can write it as..

N(N+1)/2>=100
And n=14(approx)

So we should start from 14 then move up N-1 to 13 floor I.e. 27,39…

So the floors from where the drop needs to be done are: 14,27,39,50,60,69,77,84,90,95,99,100

So the answer is 14

The requested number is 3816547290.

Tenth digit
A number is divisible by 10 if it ends on a 0. Therefore, the tenth digit of the requested number must be a 0.

Fifth digit
A number is divisible by 5 if it ends on a 0 or 5. The 0 has already been used, so the fifth digit of the requested number is a 5.

First digit
A number is always divisible by 1. Nothing can be said about the first digit.

Second digit
A number is divisible by 2 if it is even, so if it ends on a 0, 2, 4, 6, or 8. The 0 has already been used, so the second digit of the requested number is a 2, 4, 6, or 8.

The fourth, sixth, and eighth digits of the requested number must also be divisible by two, so these digits must be 2, 4, 6, or 8 too. The digits on the first, third, fifth, seventh, and ninth positions of the requested number can only be 1, 3, 5, 7, or 9.

Third digit
A number is divisible by 3 if the sum of its digits is divisible by 3. Below all possibilities for the first three digits of the requested number (first and third digits are 1, 3, 5, 7, or 9, second digit is 2, 4, 6, or 8, and the sum of the digits is divisible by 3):

    123    723    147    183    783

    129    729    741    189    789

    321    921    369    381    981

    327    927    963    387    987

Fourth digit
A number is divisible by 4 if:

• the number ends on a 0, 4, or 8 and the last-but-one digit is even, or

• the number ends on a 2 or 6 and the last-but-one digit is odd.

The third digit of the requested number is odd, so the fourth digit can only be a 2 or 6. Below are all possibilities for the first four digits of the requested number:

    1236    9216    3692    3812    7892

    1296    9276    9632    3816    7896

    3216    1472    1832    3872    9812

    3276    1476    1836    3876    9816

    7236    7412    1892    7832    9872

    7296    7416    1896    7836    9876

Sixth digit
A number is divisible by 6 if it is divisible by 2 and 3, so if it ends on a 0, 2, 4, 6, or 8, and the sum of the digits is divisible by 3. The first three digits of the requested number are already divisible by 3, so the sum of the fourth, fifth, and sixth digits must be divisible by 3 too. Below are the two possibilities for the fourth, fifth, and sixth digits of the requested number (fourth digit is 2, or 6, fifth digit is 5, sixth digit is 2, 4, 6, or 8, and the sum of the digits is divisible by 3):

    258    654

Combined with what we already know about the first five digits, this gives the following possibilities for the first sixth digits of the requested number:

    123654    723654    147258    183654    783654

    129654    729654    741258    189654    789654

    321654    921654    369258    381654    981654

    327654    927654    963258    387654    987654

Eighth digit
A number is divisible by 8 if:

• the number formed by the last two digits is divisible by 8 and the last-but-two digit is even, or

• the number formed by the last two digits minus 4 is divisible by 8 and the last-but-two digit is odd.

The last-but-two digit is the sixth digit of the requested number, and is a 4 or 8. Therefore, the number formed by the seventh and eighth digits must be divisible by 8. In addition, we know that the seventh digit must be odd. These are the possible combinations:

    16    32    56    72    96

Combined with what we already know about the first six digits, this gives the following possibilities for the first eight digits of the requested number:

    18365472    74125896

    18965432    78965432

    18965472    98165432

    38165472    98165472

    14725896    98765432

Seventh digit
The number formed by the first seven digits of the requested number must be divisible by 7. For the numbers shown above, this only holds for the number 38165472.

Ninth digit
For the ninth digit, only the digit 9 remains. Note that every number formed by the digits 1 up to 9 is divisible by 9. A number is divisible by 9 if the sum of its digits is divisible by 9. The sum of the digits 1 up to 9 is 45, which is divisible by 9.

Conclusion
The requested number is 3816547290.