Please type your explanation It will be greatly appreciatedS

Please type your explanation!!!!! It will be greatly appreciated.

Solution

It\'s an assumtion. The number of terms is made that way , for example 9 in binary is 1001 so if we group them in block of three from right to left then 1 will remains which is alone. Now if we add 00 in the binary string like 001001 then it still is 9 but now we can make two groups of 3 numbers in them.