Question

2. Find the sum:
(i). 34 + 32 + 30 + ... + 2

Answer 1

Answer:

the series of the numbers are in AP,

as they have same common difference 'd',

32-34=30-32=d

d=-2

the first term of the AP is, a=34

last term =l=2

l= a+(n-1)d

2=34+(n-1)(-2)

-32=-2n+2

-34=-2n

n=17

sum of n terms= n/2[2a+(n-1)d]

=17/2[2(34)+16(-2)]

=17/2[68-32]

=17/2[36]

=17*18

=306

I hope it helps you mate!!!!!!