Download App

Probability — Maths STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceMathsProbability1 Mark
Question
Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that
first ball is black and second is red.
✓

Answer

Total number of balls = 18

Number of red balls = 8

Number of black balls = 10

Probability of getting first ball black $=\frac{10}{18}=\frac{5}{9}$

The ball is replaced after the first draw.

Probability of getting second ball as red $=\frac{8}{18}=\frac{4}{9}$

Therefore, probability of getting first ball as black and second ball as red $=\frac{5}{9}\times\frac{4}{9}=\frac{20}{81}$

 

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

Explore more

More "1 Marks" from Probability→Probability — all question types→Maths STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Find the position vector of a point which divides the join of points with position vectors $\overrightarrow{\text{a}} - \overrightarrow{\text{2b }} $ and $\overrightarrow{\text{2a}} +\overrightarrow{\text{b}}$externally in the ratio 2:1.
→
Evaluate $\int_0^1 \frac{\left(x^2-x\right)}{\sqrt{x}} d x$.
→
Given two independent events A and B such that $\text{P}(\text{A})=0.3,\ \text{P}(\text{B})=0.6.\ \text{Find}$

$\text{P}(\text{A}\ \text{and not}\ \text{B})$

 

→
Find adjoint of the matrix $\left|\begin{array}{ll}1 & 2 \\ 3 & 4\end{array}\right|$
→
Compute the magnitude of the following vectors:
$\vec{a}=\hat{i} + \hat{j}+\hat{k;}$  $ \vec{b}=2\hat{i}-7\hat{j}-3\hat{k};$ $ \vec{c}=\frac{1}{\sqrt{3}}\hat{i}+\frac{1}{\sqrt{3}}\hat{j}-\frac{1}{\sqrt{3}}\hat{k}$
→
Find the integral: $\int \frac{d x}{x^{2}-16}$
→
Evaluate:

 $ \begin{vmatrix} \text{cos 15}^{0}& \text{sin 15}^{0} \\ \text{sin 75}^{0} & \text{cos 75}^{0} \\ \end{vmatrix}$.

→
g: {5, 6, 7, 8} → {1, 2, 3, 4} with
g = {(5, 4), (6, 3), (7, 4), (8, 2)}
→
Find the values of a and b such that the function defined by
f(x) = $\begin{cases}5, & \text { if } x \leq 2 \\ a x+b, & \text { if } 2<x<10 \\ 21, & \text { if } x \geq 10\end{cases}$ is a continuous function.
→
If A is a $3 \times 3$ invertible matrix, then what will be the value of k if $\text{det(A}^{-1}) = (\text{det(A)}^{\text{k}}.$
→