Waste less time on Facebook — follow Brilliant.
×

Help needed!!

Plz i request u to post a solution for this as I don't know the correct answer

A bag contains 3 maths books and 2 physics books. A book is drawn at random, if it is of maths, 2 more books of maths together with this book put back in the bag and if it is of physics it is not replaced in the bag.This experiment is repeated 3 times.If third draw gives maths book,what is the probability that first two drawn books were of physics.

Note by Tanishq Varshney
2 years, 9 months ago

No vote yet
1 vote

  Easy Math Editor

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold

- bulleted
- list

  • bulleted
  • list

1. numbered
2. list

  1. numbered
  2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1

paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
    # 4 spaces, and now they show
    # up as a code block.

    print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in \( ... \) or \[ ... \] to ensure proper formatting.
2 \times 3 \( 2 \times 3 \)
2^{34} \( 2^{34} \)
a_{i-1} \( a_{i-1} \)
\frac{2}{3} \( \frac{2}{3} \)
\sqrt{2} \( \sqrt{2} \)
\sum_{i=1}^3 \( \sum_{i=1}^3 \)
\sin \theta \( \sin \theta \)
\boxed{123} \( \boxed{123} \)

Comments

Sort by:

Top Newest

We have to use Bayes theorem right ? Calculate probability for the four events separately like MMM , MPM , etc. It will be a messy answer

Rohit Shah - 2 years, 9 months ago

Log in to reply

ya u r correct,its a question from one of my friends quiz test paper

Tanishq Varshney - 2 years, 9 months ago

Log in to reply

Is the answer 42/347?

Rajorshi Chaudhuri - 2 years, 9 months ago

Log in to reply

i guess it should be \(\frac{42}{357}\) which is equal to \(\frac{2}{17}\)

Kyle Finch - 2 years, 9 months ago

Log in to reply

i don't know the answer @Rajorshi Chaudhuri .. can u post ur method in brief

Tanishq Varshney - 2 years, 9 months ago

Log in to reply

I solved it as: Let math book be M and physics book be P. So the last book is M and it can be with MMM, MPM, PMM, PPM. Now, P(MMM)=(3/5)(5/7)(7/9)=1/3. Similarly for the rest. And out of this we need PPM.

Rajorshi Chaudhuri - 2 years, 9 months ago

Log in to reply

@Rajorshi Chaudhuri ok! now i understood, thanx :)

Tanishq Varshney - 2 years, 9 months ago

Log in to reply

×

Problem Loading...

Note Loading...

Set Loading...