Download App

Probability — MATHS STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceMATHSProbability1 Mark
Question
Choose the correct answer from the given four options.Three persons, A, B and C, fire at a target in turn, starting with A. Their probability
of hitting the target are 0.4, 0.3 and 0.2 respectively. The probability of two hits
is:
✓

Answer

  1. 0.188
Solution:
We have
$\text{P}(\text{A})=0.4,\text{P}(\bar{\text{A}})=0.6,\text{P}(\text{B})=0.3,\text{P}(\bar{\text{B}})=0.7$
$\text{P}(\text{C})=0.2$ and $\text{P}(\bar{\text{C}})=0.8$
$\therefore$ Probability of two hits $=\text{P}_{\text{A}}\cdot\text{P}_{\text{B}}\cdot\text{P}_{\bar{\text{C}}}+\text{P}_{\text{A}}\cdot\text{P}{_\bar{\text{B}}}\cdot\text{P}_{\text{C}}+\text{P}{_\bar{\text{A}}}\cdot\text{P}_{\text{B}}\cdot\text{P}_{\text{C}}$
$=0.4\times0.3\times0.8+0.4\times0.7\times0.2+0.6\times0.3\times0.2$
$=0.096+0.056+0.036=0.188$

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 "M.C.Q (1 Marks)" from Probability→Probability — all question types→MATHS STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

Choose the correct option from given four options:
If $\int\frac{\text{dx}}{(\text{x}+2)(\text{x}^2+1)}=\text{a}\log|1+\text{x}^2|+\text{b}\tan^{-1}\text{x}+\frac{1}{5}\log|\text{x}+2|+\text{C},$ then:
  1. $\text{a}=\frac{-1}{10},\text{b}=\frac{-2}{5}$
  2. $\text{a}=\frac{-1}{10},\text{b}=-\frac{2}{5}$
  3. $\text{a}=\frac{-1}{10},\text{b}=\frac{2}{5}$
  4. $\text{a}=\frac{1}{10},\text{b}=\frac{2}{5}$
→
$\int\sec^2\text{x}.\text{cosec}^2\text{xdx}=$
  1. $\tan\text{x}-\cot\text{x+c}$
  2. $\tan\text{x}+\cot\text{x+c}$
  3. $-\tan\text{x}+\cot\text{x+c}$
  4. $\sec\text{x}\tan\text{x+c}$
→
If a binary operation * is defined on the set Z of integers as a * b = 3a − b, then the value of (2 * 3) * 4 is:
  1. 2
  2. 3
  3. 4
  4. 5
→
If I is a unit matrix, then 3I will be
→
Optimization of the objective function is a process of
→
If $a x^2+2 h x y+b y^2=1$, then $\frac{d y}{d x}$ equals
→
The degree of the differntial equation $\left\{5+\Big(\frac{\text{dy}}{\text{dx}}\Big)^{2}\right\}^{\frac{5}{3}}=\text{x}^{5}\Big(\frac{\text{d}^{2}\text{y}}{\text{dx}^{2}}\Big)$ is:
  1. 4
  2. 2
  3. 5
  4. 10
→
Which of the following is true?
  1. * defined by $\text{a}*\text{b}=\frac{\text{a + b}}2$ is a binary operation on Z.
  2. * defined by $\text{a}*\text{b}=\frac{\text{a + b}}2$ is a binary operation on Q.
  3. All binary commutative operations are associative.
  4. Subtraction is a binary operation on N.
→
A relation R is defined as $R =\{(1,2)\}$ on set $A =$ $\{1,2,3\}$, then R is :
→
Probability that $A$ speaks truth is $\frac{4}{5}. A$ coin is tossed. $A$ reports that a head appears. The probability that actually there was head is
→