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If the set of natural numbers is partitioned into subsets `S_1={1},S_2={2,3},S_3={4,5,6}`and so on then find the sum of the terms in `S_(50)dot` |
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Answer» The number of terms in the groups are `1,2,3,"...."` `therefore` The number of terms in the 50th group =50 `therefore` The last term of 1st group = 1 The last term of 2nd group `=3=1+2` The last term of 3rd group `=6=1+2+3` `vdots " "vdots " "vdots " "vdots " "vdots " "vdots` The last term of 49th group `=+2+3+"......" + 49` `therefore` First term of 50th group `=1+(1+2+3+"..."+ 49)` `=1+(49)/(2)(1+49)=1226` `therefore S_(50_=(50)/(2){2xx1226+(50-1)xx1}` `=25xx2501=62525` |
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