5 votes 5 votes Consider this GATE 2003 question: https://gateoverflow.in/937/gate2003-46 Here, instead of XOR gates we had OR gates, then which of the following operations can we perform? $A + B, A - B\ and\ A + 1$ CO and Architecture gatecse-2003 adder + – Rishabh Gupta 2 asked Nov 3, 2017 Rishabh Gupta 2 1.2k views answer comment Share Follow See all 6 Comments See all 6 6 Comments reply joshi_nitish commented Nov 3, 2017 reply Follow Share if 2's complement arthemetic is used, then among given options only A+B can be manipulated.. 0 votes 0 votes Rishabh Gupta 2 commented Nov 3, 2017 reply Follow Share What do you mean by "if 2's complement arthemetic is used" ?? And what about A + 1. when K = 1 and C0 = 0 ?? 0 votes 0 votes Anu007 commented Nov 3, 2017 reply Follow Share yes A+B when k= 1 and c=0 A+1 again cannot perform. with AND gate we can perform that A-B is also not perform. 1 votes 1 votes joshi_nitish commented Nov 3, 2017 reply Follow Share And what about A + 1. when K = 1 and C0 = 0 ?? it will not perform A+1 in this case, instead it will perform A-1.... it will be like, an-1an-2an-3.....a0 + 1111.....11 // all 1's in 2's complement represent -1, so finally it will be an-1an-2an-3.....a0 - 1 = A-1 7 votes 7 votes Rishabh Gupta 2 commented Nov 3, 2017 reply Follow Share Thanks :) 1 votes 1 votes neeraj_bhatt commented Nov 5, 2019 reply Follow Share @joshi_nitish The A-1 part was really good. Thanks. 0 votes 0 votes Please log in or register to add a comment.