Without adding, find the sum

(i) 1 + 3 + 5 + 7 + 9

(ii) 1 + 3 + 5 + 7 + 9 + I1 + 13 + 15 + 17 +19

(iii) 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21 + 23

(i) As per the question, we have to find the sum of first five odd natural numbers.


Therefore,


1 + 3 + 5 + 7 + 9


= (5)2


= 25


(ii) As per the question, we have to find the sum of first ten odd natural numbers


Therefore,


1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19


= (10)2


= 100


(iii) As per the question, we have to calculate the sum of first twelve odd natural numbers


Therefore,


1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 +17 + 19 + 21 + 23


= (12)2


= 144

16