Number 15 in binary form

Answer 1

Rather than tell you what the answer is, I think it better that you learn how to do this your self. By asking the question you must realize that each binary digit can have a value of one or zero. Just like with decimal numbers, the digit of lest value is on the right and has a decimal value of one. The digit immediately to its left has a value that is twice that of it neighbor to the right and also half the value of its neighbor to the left.

Here is the decimal values of 8 binary digits.

[128][64][32][16][8][4][2][1] decimal value

( 8)( 7)( 6)( 5)(4)(3)(2)(1) digit place

Lets convert 25 decimal into binary.

The largest decimal value that can be subtracted is 16 with 3 digits to the left, write down 3 zeros as place holders for the 3 left digits. Follow by a one.

0001

25 - 16 = 9

The next binary digit to the right has a decimal value of 8 and can be subtracted from 9 so we write down another 1.

00011

9 - 8 = 1

Now for each binary digit that has a decimal value greater than the remainder write a zero.

0001100

Now there is just the 1 left to deal with. Any time there is only 1 left you can just write down a 1.

00011001

So with that short intro to converting decimal into binary you should be dangerous enough to do your own decimal to binary conversions. (If still in doubt try, Google for an explanation that makes more sense to you).

Answer 2

15110 = 100101112

Answer 3

17 17

Answer 4

1111