Question

How much smaller is the sum of the first 1000 natural numbers than the sum of the first 1001 natural numbers?

Answer 1

ANSWER

1001

EXPLANATION

The sum of the first n - natural numbers is

$S_n= \frac{n}{2} (2a + d(n - 1))$

The sum of the first 1000 terms is

$S_{1000}= \frac{1000}{2} (2(1) + 1(1000 - 1))$

$S_{1000}=500 (1001)$

$S_{1000}=500500$

The sum of the first 1001 terms is

$S_{1001}= \frac{1001}{2} (2(1) + 1(1001 - 1))$

$S_{1001}= 1001 \times (501)$

$= 501501$

The difference is

$501501 - 500500= 1001$

Answer 2

Answer:

The answer to this questions is 1001.