Turn on thread page Beta
    • Thread Starter

    Box A contains 5 red paper clips and 1 white paper clip. Box B contains 7 red paper clips and 2 white paper clips. One paper clip is taken at random from box A and transferred to box B. One paper clip is then taken at random from box B.
    (i) Find the probabilityof taking both a white paper clip from box A and a red paper clip from box B.
    (ii) Find the probability that the paper clip taken from box B is red.
    (iii) Find the probability that the paper clip taken from box A was red, given that the paper clip taken from box B is red.
    (iv) The random variable X denotes the number of times that a red paper clip is taken. Draw up a table to show the probability distribution of X.
    Please help me out on solving as my exams are near.
    • Thread Starter


    For a, the prob of a white is 1/6. This changes the numbers in box B, but you can work out prob of red.
    If you quickly work out the probs of (w, w), (w, r), (r, w) and (r,r) the rest should be easy to complete.
Submit reply
Turn on thread page Beta
Updated: October 10, 2017

University open days

  • Manchester Metropolitan University
    Postgraduate Open Day Postgraduate
    Wed, 14 Nov '18
  • University of Chester
    Chester campuses Undergraduate
    Wed, 14 Nov '18
  • Anglia Ruskin University
    Ambitious, driven, developing your career & employability? Aspiring in your field, up-skilling after a career break? Then our Postgrad Open Evening is for you. Postgraduate
    Wed, 14 Nov '18
Have you ever experienced bullying?
Useful resources

Make your revision easier


Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here


How to use LaTex

Writing equations the easy way


Best calculators for A level Maths

Tips on which model to get

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