Question

I need help with this question.

Answer 1

Answer:

$\displaystyle S_{27}=675$

Step-by-step explanation:

The sum of N consecutive natural numbers is given by:

$\displaystyle S_N=\frac{N}{2}(F+L)$

We need to find the sum of the natural numbers between 12 to 38.

To calculate the required sum we have F=12, L=38, but we don't have the value of N.

From 12 to 38 there are 38 - 12 + 1 = 27 natural consecutive numbers, thus N=27.

Substituting in the formula:

$\displaystyle S_{27}=\frac{27}{2}(12+38)$

$\displaystyle S_{27}=\frac{27}{2}(50)$

$\displaystyle S_{27}=27*25$

$\mathbf{\displaystyle S_{27}=675}$