Hiiiii dear_______✌️✌️✌️✌️✌️Given ratio of sum of n terms of two AP’s = (2n+1):(2n+5)Let’s consider the ratio these two AP’s 10th terms as A10 : a’10 →(2)Recall the 10th term of AP formula, an = a + 9dHence EQUATION (2) becomes,a10 : a’10 = a + 9d : a’ + 9d’On MULTIPLYING by 2, we geta10 : a’10 = [2a + 2*9d] : [2a’ + 2*9d’]= [2a + 18D] : [2a’ + 18d’]=( S2) 10th – 1 : (S’2) 10th – 1= [2(10 )+ 1] : [2(10 )+5] [from (1)]= 21 : 25Thus the ratio of 10th terms of two AP’s is 21:25
Your experience on this site will be improved by allowing cookies. Read Cookie Policy