Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta

Statistics probability question , please help (as level) cie watch

    • Thread Starter
    Offline

    10
    ReputationRep:
    I have solved the first two questions , I just need the answer for the last part , any help would be great ! Thank you . Please do explain thoroughly.


    An English examination consists of 8 questions in Part A and 3 questions in Part B. Candidates must choose 6 questions. The order in which questions are chosen does not matter. Find the number of ways in which the 6 questions can be chosen in each of the following cases.
    (i) There are no restrictions on which questions can be chosen. [1]
    (ii) Candidates must choose at least 4 questions from Part A. [3]
    (iii) Candidates must either choose both question 1 and question 2 in Part A, or choose neither of these questions.
    Posted on the TSR App. Download from Apple or Google Play
    Online

    9
    ReputationRep:
    Case 1: You choose both questions, so you have to choose 4 more from the 9 remaining. (9C4 ways)

    Case 2: You choose neither. So you have to choose 6 questions from the 9 remaining. (9C6 ways)
    • Thread Starter
    Offline

    10
    ReputationRep:
    (Original post by BobbJo)
    Case 1: You choose both questions, so you have to choose 4 more from the 9 remaining. (9C4 ways)

    Case 2: You choose neither. So you have to choose 6 questions from the 9 remaining. (9C6 ways)
    I do not get it , Can u please explain it in another way if that’s possible ?
    Posted on the TSR App. Download from Apple or Google Play
    Online

    9
    ReputationRep:
    (Original post by Sammysammy99)
    I do not get it , Can u please explain it in another way if that’s possible ?
    Candidates have to choose 6 questions.

    If they choose question 1 and 2, they have to choose 4 more from what's left.

    If they don't choose question 1 and 2, then they have to choose 6 from what's left.
    • Thread Starter
    Offline

    10
    ReputationRep:
    (Original post by BobbJo)
    Candidates have to choose 6 questions.

    If they choose question 1 and 2, they have to choose 4 more from what's left.

    If they don't choose question 1 and 2, then they have to choose 6 from what's left.
    Alright thank you very much I get it now
    Posted on the TSR App. Download from Apple or Google Play
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: March 12, 2018
Poll
Do I go to The Streets tomorrow night?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.