Question

3. Without actual calculations, find the following sums.
(1) 1+3+5+7+9+11
(ii) 1+3+5+7 + 9 + 11 +13 + 15 + 17 +19+21
(iii) 11 +13 + 15 +17+19+21 +23+25+27 +29
(iv) 13+ 15 + 17 +19+21 +23​

Answer 1

3. Without actual calculations, find the following sums.

(1) 1+3+5+7+9+11

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

(iii) 11 +13 + 15 +17+19+21 +23+25+27 +29

(iv) 13+ 15 + 17 +19+21 +23

Answer:

36

121

225

108