0 votes 0 votes Let T be a set of integers {3,11,19,27,....451,459,467} and S be a subset of T such that the sum of no two elements of S is 470. The maximum number of elements in S is? a)32 b)28 c)29 d)30 Sambhrant Maurya asked Jul 28, 2018 Sambhrant Maurya 550 views answer comment Share Follow See 1 comment See all 1 1 comment reply Prateek Raghuvanshi commented Jul 28, 2018 reply Follow Share I think option c is right answer. 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes its the problem of A.P.. where a= 3, d=8 , and l=467. using formulae a+(n-1)*d=l n=59. so floor(59/2) sum to 470.. (as sum of a term equidistant from ends are 470 except the middle one) 29 is answer . C arvin answered Jul 28, 2018 arvin comment Share Follow See all 4 Comments See all 4 4 Comments reply Sambhrant Maurya commented Jul 28, 2018 reply Follow Share Why didn't you consider the middle term in the subset? 0 votes 0 votes arvin commented Jul 28, 2018 reply Follow Share cuzz it doesnot satisfies the solution protocol. 0 votes 0 votes Sambhrant Maurya commented Jul 28, 2018 reply Follow Share care to elaborate? 0 votes 0 votes Prateek Raghuvanshi commented Jul 29, 2018 reply Follow Share @Sambhrant Maurya,S is the subset of T which satisfies the condition as you can see S can have elements {(3,467) (11,459)(19,451)..........} as you can see total no. of elements are 59 and condition is satisfying in pair of equidistant from front and last .so there will be left one element in the middle which will not pair up with anyone.so only 29 pairs will be there which elements of subset S. 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes I think the answer is D. Considering the middle term which is 235, it won't make the sum 470 with any other item in the set. So 29 terms by solving the A.P. Series and one middle term also. D) 30 Rishabh Agrawal answered Jul 29, 2018 Rishabh Agrawal comment Share Follow See 1 comment See all 1 1 comment reply Sambhrant Maurya commented Jul 29, 2018 reply Follow Share The answer is 29. I am in a dilemma too with this middle term. 0 votes 0 votes Please log in or register to add a comment.