Plz expain how to solve dis... 25 . T h e s e t s S 1 , S 2 , S 3 . . . . . . . . a r e g i v e n b y S 1 = 2 1 , S 2 = 3 2 , 5 2 , S 3 = 4 7 , 7 3 ' 10 3 , S 4 = 5 4 , 9 4 , 13 4 , 17 4 , . . . . . . . t h e n t h e s u m o f t h e n u m b e r s i n t h e s e t S 25 i s 1 ) 322 2 ) 324 3 ) 325 4 ) 326 Share with your friends Share 1 Lovina Kansal answered this Dear student As we observe that the suffix of the set represents the number of elements in that set.Example:In S2, suffix is S2.So, S2 contains two elements.and the common difference between each term emement is 1So, S25=2625,5125,7625,...,62625Clearly,it is an AP with first term,a=2625 and d=5125-2625=1So, Sum of elements of S25=25222625+(25-1)1 ∵Sum of n terms of AP=n22a+(n-1)d=2525225+24=252×52+60025=6522=326∴Sum of elements of S25=326 Regards 1 View Full Answer Raj Seth answered this Try to analyse the question, you will find the trend followed by the series. That is the key for this question. See my solution .hope this helps 1
