Question
A bag contains 5 brown and 4 white socks. A man pulls out two socks. The probability that these are of the sane colour is.
  1. $\frac{5}{108}$
  2. $\frac{18}{108}$
  3. $\frac{30}{108}$
  4. $\frac{48}{108}$

Answer

  1. $\frac{48}{108}$
Solution:
Total number of balls = 5brown + 4white = 9
Required probability $=\frac{5}{9}\times\frac{4}{8}+\frac{4}{9}\times\frac{3}{8}=\frac{4}{9}$
$\Rightarrow\ \frac{4\times12}{9\times12}=\frac{48}{108}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If two events $A$ and $B$ are independent, then which of the following is true about events $A$ and $B ?$
The interval on which the function $f(x) = 2x^3 + 9x^2 + 12x - 1$ is decreasing is:
$\int\text{e}^{\text{x}}\{\text{f(x)}+\text{f}'(\text{x})\}\text{dx}=$
  1. $\text{e}^{\text{x}}\text{f(x)}+\text{C}$
  2. $\text{e}^{\text{x}}+\text{f(x)}$
  3. $2\text{e}^{\text{x}}\text{f(x)}$
  4. $\text{e}^{\text{x}}-\text{f(x)}$
Choose the correct answer in Exercise: The value of $\int^{\frac{\pi}{2}}\limits_{\frac{-\pi}{2}}\text{(x}^{3}+\text{x}\cos\text{x}+\tan^{5}\text{x}+1)\text{dx}\ $is
  1. 0
  2. 2
  3. $\pi$
  4. 1
The value of $\hat{\text{i}}.\big(\hat{\text{j}}\times\hat{\text{k}}\big)+\hat{\text{j}}.\big(\hat{\text{i}}\times\hat{\text{k}}\big)+\hat{\text{k}}.\big(\hat{\text{i}}\times\hat{\text{j}}\big),$ is:
  1. 0
  2. -1
  3. 1
  4. 3
Smaller area enclosed by the circle $x^2 + y^2 = 4$ and the line $x + y = 2$ is:
Choose the correct answer:$\text{Let}\ \vec{\text{a}}\ \text{and}\ \vec{\text{b}}$ be two unit vectors and $\theta$ is the angle between them. Then $\vec{\text{a}}+\vec{\text{b}}$ is a unit vector if,
  1. $\theta=\frac{\pi}{4}$
  2. $\theta=\frac{\pi}{3}$
  3. $\theta=\frac{\pi}{2}$
  4. $\theta=\frac{2\pi}{3}$
Three integers are chosen at random from the first 20 integers. The probability that their product is even is,
R is a relation on the set Z of integers and it is given by (x, y) ∈ R ⇔ | x - y | ≤ 1. Then, R is:
  1. Reflexive and transitive.
  2. Reflexive and symmetric.
  3. Symmetric and transitive.
  4. An equivalence relation.
What are the DR's of vector parallel to (2, −1, 1) and (3, 4, −1)?