Question

sum of even numbers till 300​

Answer 1

Answer: a1 = 2 and an = 300

so, 2 + 4 + 6 + ...................300

Taking 2 as common 2 ( 1 + 2 + 3 +........150)

sn = n ( n +1 )/2

150 x 151 /2

22,650

Answer 2

Answer:

22,650

Step-by-step explanation:

Given :

First term ( a ) = 2

Last term ( t_n ) = 300

Common difference ( d ) = 2

We have term formula

t_n = a + ( n - 1 ) d

300 = 2 + ( n -1 ) 2

2 ( n - 1 ) = 298

n - 1 = 149

n = 150

So numbers of terms is 150

Now we have sum formula

S_n = n / 2 ( a + l )

where l is last term.

$\displaystyle S_{150}=\frac{150}{2}(2+300) \\\\\displaystyle S_{150}=\frac{150}{2}(302) \\\\\displaystyle S_{150}=75\times302\\\\\displaystyle S_{150}=22,650$

Thus we get answer.