Hello Sezi!

The decimal number 25 in binary would be 11001. Now that's the required answer. In order to convert any decimal N into binary, find the greatest power of 2 that is smaller than N, subtract that number from N and set its corresponding bit to 1 and continue the same process ie if powers of 2 is greater than differences obtained then set the corresponding bit as 1 and if not then 0, continue the same process till you reach zero to get the required answer.

Hope it helped you.