Hi, could someone tell me if I've done this correctly?

For the progression 1,4,7,10, .... state the

50th term and the sum of the first 50 terms.

I have 50th term as 148

I have sum of first 50 as 1475...

Cheers.

Printable View

- May 7th 2007, 01:40 PMbobchibaProgression - Am I right?
Hi, could someone tell me if I've done this correctly?

For the progression 1,4,7,10, .... state the

50th term and the sum of the first 50 terms.

I have 50th term as 148

I have sum of first 50 as 1475...

Cheers. - May 7th 2007, 02:00 PMCaptainBlack
- May 7th 2007, 02:09 PMbobchiba
regarding the sum,

I was shown in a previous thread a while ago that

Sn = n(a1 + an) / 2

so I ended up with 25( 1 + a20) - May 7th 2007, 02:12 PMbobchiba
sorry....just realised my mistake, should have been a50 not a20....it works out now,

thank you. - May 7th 2007, 02:13 PMCaptainBlack