Question

sum of all positive integers from 1 to 821. Pease include explanation and work. I will reward the correct answer.

Answer 1

Answer:

337431

Step-by-step explanation:

first term = a = 1

last term = l = 821

common difference = d = 1

l = a+(n-1)d = 821

1+(n-1)1 = 821

n-1 = 820

n = 821

sum = n/2 x (a+l)

= 821/2 x 822 = 821x 411 = 337431

(I have used Arithmetic Progression here to solve the sum)

hope it helps :)