SOLUTION: If, the first number of an arithmetic sequence is 200, and the 100th number is 2, what is the 40th number of this sequence?

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Question 451663: If, the first number of an arithmetic sequence is 200, and the 100th number is 2, what is the 40th number of this sequence?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

arithmetic sequence

a%5Bn%5D=a%5B1%5D%2B%28n-1%29%2Ad

a%5B100%5D=200%2B%2899%29%2Ad+=+2

           99*d = -198

               d = -2

a%5B40%5D=200%2B%2839%29%2A-2+=+122