642?

The Gateway to Computer Science Excellence

+2 votes

Best answer

If base is r and you need to find r's complement then first find (r-1)'s complement.

Follow these steps:-

1. Subtract each digit of the given number from (r-1).

Here r=9 so r-1=8. Subtract 247 from 888 to get 641.

2. Then add 1 to it. 641+1=642

You can verify it for binary numbers, r=2. Say N=1011 then 1's complement is 0100. How we get it? By subtracting each digit drop from 1. So 1111-1011=0100. And add 1 so 2's complement becomes 0101.

Follow these steps:-

1. Subtract each digit of the given number from (r-1).

Here r=9 so r-1=8. Subtract 247 from 888 to get 641.

2. Then add 1 to it. 641+1=642

You can verify it for binary numbers, r=2. Say N=1011 then 1's complement is 0100. How we get it? By subtracting each digit drop from 1. So 1111-1011=0100. And add 1 so 2's complement becomes 0101.

- All categories
- General Aptitude 1.9k
- Engineering Mathematics 7.5k
- Digital Logic 2.9k
- Programming and DS 4.9k
- Algorithms 4.4k
- Theory of Computation 6.2k
- Compiler Design 2.1k
- Databases 4.1k
- CO and Architecture 3.4k
- Computer Networks 4.2k
- Non GATE 1.4k
- Others 1.4k
- Admissions 595
- Exam Queries 573
- Tier 1 Placement Questions 23
- Job Queries 72
- Projects 18

50,737 questions

57,279 answers

198,174 comments

104,840 users