Question

Without actual addition, find the sum of the following:
a) 1 + 3 + 5 + 7 + 9 + 11​

Answer 1

Answer:

36

Step-by-step explanation:

1 + 3 + 5 + 7 + 9 + 11

= 11+9 = 20 , 7 + 3 = 10 , 5 + 1 = 6

= 20 + 10 + 6

= 36

Answer 2

Answer:

36

Step-by-step explanation:

1. As we can see all these numbers are odd serial wise.

2. We can calculate their sum by counting them.

3. 1+3+5+7+9+11 are 6 in number

4. Square the obtained number.

(6) × (6) = 36

5. Hence 36 is the right answer.