Question

plese solve this question

Answer 1

Answer:

Step-by-step explanation:

3,6......999

a=3

d=3

L=a+(n-1)d

999=3+(n-1)3

996=3n-3

999=3n

n=333

Now,

N/2(a+l) ,to calculate sum

333/2(3+999)

333/2*1002

166833 is the answer

Answer 2

1,3,5,7.......999

Here,a=1,d=2,tn=999

tn=a+(n-1)d

999 =1+(n-1)2

999=1+2n-2

999=-1+2n

1000=2n

n=500

Sn=n/2(2a+(n-1)d)

S500=500/2*2 +(500-1)2

=250×2+499×2

=500+998

=1498

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