Question

A student may answer any six of
ten questions on an examination.
(a) In how many ways can six questions be selected?
(b) How many selections are possible if the first two questions
must be answered?

Answer 1

Do you know Combinations??

Answer 2

c(n,k )

Answer 3

i don't know how transalte the words in numbers

Answer 4

Okay so you have 10 questions and you need to select 6. Its just a combination C( 10 , 6)

Answer 5

that's all

Answer 6

c = 10!/(4!)6! ?

Answer 7

Yeah and do you want help for second part aswell???

Answer 8

the second one is a peRMUTATion ?

Answer 9

No!! even thats a combination

Answer 10

You must answer first two, so you have to select 4 from remaining 8 thats it!!

Answer 11

Got it??

Answer 12

Okay I'm leaving the answer is C (8,4). Remember one thing when there is a selection of objects its a combination. When we have to select and arrange objects then that's a permutation

Answer 13

ok thanks a lot!

Answer 14

c = 8!/(4!) 4!