Question

Find the sum of all even numbers from 25 to 50.

Answer 1

Answer:

26+28+30+32+34+36+38+40+42+44+46+48+50=494

Answer 2

Answer:

324

Step-by-step explanation:

Numbers are from 25 to 50

First Even number between 25 to 50 is 26

Second even number between 25 to 50 is 28

Last even number between 25 to 50 is 48

So, Common difference between two even numbers is 2

AP : 26,28 ......  , 48

So, a = first term = 26

d = 2

$a_n=48$

Formula of nth term = $a_n=a+(n-1)d$

$48=26+(n-1)4$                  

$22=(n-1)2$                

$11=(n-1)$          

$12=n$                                                

Sum of n terms = $\frac{n}{2}(a+a_n)$

                         =$\frac{12}{2}(26+28)$

                         =$6(26+28)$

                         =$324$

Hence  the sum of all even numbers from 25 to 50 is 324