Word Tranlations Chap 6 No. 6 Fourth Edition

[afvatcha]

Hi,

I looked at no. 6 of chapter 6 in the word tranlations book. The answer is 244.5. The answer key says 6 + (159 x 3)=483. 483/2=244.5.

My question is why is it 159 x 3. If there are 160 terms, shouldnt it be (160 x 3) + 6?

Thanks,
Anosh

[mithunsam]

Last term is calculated as first term + (n-1)d, where d is the difference and n is the number of terms.

So, it is 6 + (160-1)3 = 6+159*3 = 483

Alternatively, you can also write last term as 161 * 3 = 483

1st term is 6 = 3.2
2nd term is 9 = 3.3
3rd term is 12 = 3.4
---
---
160th term will be 483 = 3.161

Does that make sense?

[afvatcha]

Last term is calculated as first term + (n-1)d, where d is the difference and n is the number of terms.

So, it is 6 + (160-1)3 = 6+159*3 = 483

Alternatively, you can also write last term as 161 * 3 = 483

1st term is 6 = 3.2
2nd term is 9 = 3.3
3rd term is 12 = 3.4
---
---
160th term will be 483 = 3.161

Does that make sense?

Hi, Thanks! Where did you get this formula? Is it possible for an instructor who can verify this?

[mithunsam]

The formula is mentioned in OG.

You can think in this way...
You have the first term, say 1 and the difference between terms is 3
Now what is 9th term?
9th term is 8 terms away from the first term.

Therefore, it is 1 + 8*3 = 25. In another words 1 + (9-1)3 = 25. (Where n = 9 and d = 3 in this particular example )

Last term is calculated as first term + (n-1)d, where d is the difference and n is the number of terms.

So, it is 6 + (160-1)3 = 6+159*3 = 483

Alternatively, you can also write last term as 161 * 3 = 483

1st term is 6 = 3.2
2nd term is 9 = 3.3
3rd term is 12 = 3.4
---
---
160th term will be 483 = 3.161

Does that make sense?

Hi, Thanks! Where did you get this formula? Is it possible for an instructor who can verify this?

[jnelson0612]

Thanks all, and yes, consider this formula verified.