math problem help

[sonoma1993]

I need help with this math problem,

Add the odd numbers from 5 to 371.

Hint This is an arithmetic series

here the answer I have a choice from

69184
34404
376
34592
68808

according to the formula im using n/2 * (a1 + an)

i get the answer 34968

 

[tfinch2]

Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

 

[GeneValgene]

Originally posted by: tfinch2
Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

-edit-

oops...sorry. the correct answer is 34592. that includes both the 5 and 371

 

[Anubis]

Originally posted by: GeneValgene

Originally posted by: tfinch2
Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

LOL

pwned

why owned, it didnt say to exclude them, i would have most likely included them as well

 

[dullard]

Originally posted by: Anubis
why owned, it didnt say to exclude them, i would have most likely included them as well

You are supposed to include them. But sonoma1993 included them twice.

 

[GeneValgene]

Originally posted by: Anubis

Originally posted by: GeneValgene

Originally posted by: tfinch2
Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

LOL

pwned

why owned, it didnt say to exclude them, i would have most likely included them as well

you're right...if you include both of them, the answer is 34592

 

[Gibson486]

I think it is the last one, but i am not good at sequences and series.

edit
nm, the last is if it is all numbers.....

 

[sonoma1993]

Originally posted by: tfinch2
Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

im sure I included it into the forumla

i think the forumla should look somethen like this if not please correct it

188/2 * (5+371)

 

[tfinch2]

Originally posted by: dullard

Originally posted by: Anubis
why owned, it didnt say to exclude them, i would have most likely included them as well

You are supposed to include them. But sonoma1993 included them twice.

You're right, he did. I didn't even really look at the problem, just some logic based off his answer.

 

[hypn0tik]

Sum = (First + Last)*(# of numbers)/2
= (5 + 371)*((371-5)/2 + 1)/2
= (376)(184)/2 = 34592

 

[Anubis]

Originally posted by: dullard

Originally posted by: Anubis
why owned, it didnt say to exclude them, i would have most likely included them as well

You are supposed to include them. But sonoma1993 included them twice.

lol

 

[sonoma1993]

thanks for the help,

 

[hypn0tik]

Originally posted by: sonoma1993

Originally posted by: tfinch2
Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

im sure I included it into the forumla

i think the forumla should look somethen like this if not please correct it

188/2 * (5+371)

Should be 184/2.

The number of numbers between and including the end points can be found by:

[(last # - first #)/step size] + 1
Here, it's (371 - 5)/2 + 1 = 184

 

[dullard]

Originally posted by: sonoma1993
188/2 * (5+371)

Your formula is ok, but there aren't 188 terms.

 

[sonoma1993]

Originally posted by: hypn0tik

Originally posted by: sonoma1993

Originally posted by: tfinch2
Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

im sure I included it into the forumla

i think the forumla should look somethen like this if not please correct it

188/2 * (5+371)

Should be 184/2.

The number of numbers between and including the end points can be found by:

[(last # - first #)/step size] + 1
Here, it's (371 - 5)/2 + 1 = 184

cool thanks for the help.

 

[hypn0tik]

Originally posted by: sonoma1993

Originally posted by: hypn0tik

Originally posted by: sonoma1993

Originally posted by: tfinch2
Are you including 5 and 371?

34968 - 371 - 5 = 34592, which is one of your choices.

im sure I included it into the forumla

i think the forumla should look somethen like this if not please correct it

188/2 * (5+371)

Should be 184/2.

The number of numbers between and including the end points can be found by:

[(last # - first #)/step size] + 1
Here, it's (371 - 5)/2 + 1 = 184

cool thanks for the help.

No problem.