Question

What's the sum of 10 to 40

Answer 1

Step-by-step explanation:

sum of all no. till x =

$\frac{x(x + 1) }{2}$

sum of 10 to 40 =

$\frac{10(10 + 1)}{2} - \frac{40(40 + 1)}{2}$

$= 55 - 820$

$= 765$

.

;>♡ hope this helps