jacksonmeg
Badges: 11
Rep:
?
#1
Report Thread starter 6 years ago
#1
http://www.ocr.org.uk/Images/136156-...atistics-1.pdf
Need help with 7iib) :-(
0
reply
KieranMPK
Badges: 0
Rep:
?
#2
Report 6 years ago
#2
This question becomes a lot easier when you treat them both as one 'item'. Therefore, we have 5 people and 1 item. Then its just working out the number of combinations that contain the item, over the total number of combinations.

Considering when they are part of the group, the number of combinations can be defined as 5C3, as there are 3 spots left (two have been taken by Jill and Jo).

The number of combinations when they aren't in a group is 5C5. Therefore the probability is 5C3/(5C3 * 5C5). This comes out to 10/11.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (161)
14.45%
I'm not sure (50)
4.49%
No, I'm going to stick it out for now (330)
29.62%
I have already dropped out (33)
2.96%
I'm not a current university student (540)
48.47%

Watched Threads

View All