# Thread: BuYS: How strong is your "addition" skill a2a_show_title=1;a2a_num_services=14;

Are you sure you understand the basic addition concept?
Anyone can add the following decimal numbers:
10 + 23 + 1342, right...

But what about the following binary numbers:
1111
+1010
+0101
+1101
+1011
+1101 ???

Not to challenge anyone, but you might be amazed to see how tough this small problem could become Dedicated to fresh grads and those who are still in college. Give it a shot! and if possible, do pm me the answers.

Ofcouse, please don't use calculator ...

Rgds
b0nd  Reply With Quote

2. Just one reply (pm) so far .... anyway, I am very patient.  Reply With Quote

3. Hey guys,

I recevied couple of entries as the solution. Few are correct and I'll try to post the answer and my way of doing it soon, just busy with some very boring tasks.

Thanks for participating.

Rgds  Reply With Quote

4. By Prashant: 0101011 (Wrong)

By s1ayer: 01000011 (Correct) but he added two number first and then added third one to the sum and so on...

By Abhay: (Correct)
Ans:

We organize the binary numbers

1111
1010
0101
1101
1011
1101

Code:
Now we can use the following addition grid for 2 bits :
0+0=0
0+1=1
1+0=1
1+1=10Code:
And for 3 bits we can use grid for 2 bits and extend the addition and so on
1+1+1=10+1=11 (As 0+1=1 in rightmost column if we organize them)Hence back to the problem -->
1+0+1+1+1+1 = (1+0)+1+1+1+1 = (1)+1+1+1+1= (1+1)+1+1+1= (10)+1+1+1= (10+1)+1+1=(11)+1+1 = (11+1)+1
= (100) + 1= 101

We just put rightmost 1 of 101 below in the answer ( below the rightmost column) and carry the rest 10 above to the top of 2nd last rightmost column. And hence we proceed further adding this carry and the rest all members of the 2nd last rightmost column.

The final binary answer we get is 1000011 which is binary equivalent for 67.

And sorry for the confusing reply !!
By fb1:
Well binary addition we need to know this table
0 + 0 = 0
0 + 1 = 1
1 + 0 = 1
1 + 1 = 10

So 1111
+ 1010
= 11001
+ 00101 extra padede o
= 11110

And goes on, and becomes a huge pain, well so I would simply automate this process :
Unless and until we are strictof doing a binary addition , well convert to decimal add then convert the decimal back to binary :P
So probably everyone agree that this small bit is not easy to digest. I'll be posting my way of doing it this weekend.

cheers!  Reply With Quote

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