Question

1+3+5+7+9 find sum without adding​

Answer 1

Answer:

You can use Arithmetic progression To find it...

Step-by-step explanation:

We Know Sn (Sum of 'n' terms) = n/2 × {2a + (n-1)d}

a = First term

d = common difference

Now , In ap 1+3+5+7+9 ,

a = 1

d = +2 ( Increasing)

Then , S5 = 5/2 × { 2 × 1 + (5-1) ×2}

= 5/2 × ( 2 + 8 )

= 5/2 × 10 = 25 Answer.......