Question

please help (see attachment)

Answer 1

@amistre64 @jim_thompson5910 @freckles @dan815

Answer 2

Is this a worksheet?

Answer 3

No. It's a practice online.

Answer 4

I go to an online school, so all my "worksheets" are online practices, i suppose

Answer 5

Because I found this right now while I was googling your question http://mchenrymath2.yolasite.com/resources/Unit_7_Sequences_Series/0%20Sigma%20Notation%20and%20nth%20term%20SG%20and%20Practice%20Master.pdf

Answer 6

On the last page, last question on the right.

Answer 7

??

Answer 8

I think my practice problems come from actual worksheets because it says Advanced Mathematical concepts in the corner of the pages, which is my textbook

Answer 9

To solve this question:

We would have to do these steps:

9c5+9c6+9c7+9c8+9c9 =?

Answer 10

What's c?

Answer 11

Because it says "at least have 5 seniors"

Answer 12

at *least* 5

Answer 13

nCr = \(\huge\frac{n!}{r!(n-r)!}\)

Answer 14

Oh, right. Okay, I'll try that

Answer 15

c isn't a variable in this case, it's more like a function. It's the combination function to be exact


Instead of saying n C r, this notation may be better

\[\Large C(n,r) = \frac{n!}{r!*(n-r)!}\]

Answer 16

i don't think that it is
9c5+9c6+9c7+9c8+9c9 because 9c5 alone is 126, and the answer is 256

Answer 17

the numbers get smaller. :)

Answer 18

oh, right....duh...

Answer 19

126+84+36+9+1=256

OMG, thanks!

Answer 20

No problem :)