The Total solution for NCERT class 6-12
Weknow that the sum of n odd numbers = n2(i) 1 + 3 + 5 + 7 + 9 = (5)2 = 25 [∵ n = 5](ii) 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 = (10)2 = 100 [∵ n = 10](iii) 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21 + 23 = (12)2 = 144 [∵ n = 12]