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# Probability

10th Class - CBSE - Mathematics - 449 Questions - 0 Concepts

#### Important Questions

Q1 Subjective Hard
Shubham has to make a telephone call to his friend Nisheeth, Unfortunately he does not remember the $7$ digit phone number. But he remembers that the first three digits are $635$ or $674$, the number is odd and there is exactly one $9$ in the number. The maximum number of trials that Shubham has to make to be successful is a four digit number of the form $abcd$ then $c$ equal.

1 Verified Answer | Published on 07th 09, 2020

Q2 Subjective Hard
A coin is tosses. If it shows head, we draw a ball from a bag consisting of $3$ red balls and $4$ black balls. If it shows a tail, we throw a dice. What is the sample space of this experiment? What are the favourable cases representing the events. (i) the throw of the coin resulted in a head. (ii) a red ball is drawn.

1 Verified Answer | Published on 07th 09, 2020

Q3 Matrix Hard
Three players $A, B$ and $C$ alternatively throw a die in that order, the first player to throw a $6$ being deemed the winner. $A$'s die is fair where as $B$ and $C$ throw die with probabilities $p_1$ and $p_2$ respectively of throwing a $6$
 If $p_1=\dfrac15, p_2=\dfrac14$ the probability that $A$ wins the game. $\dfrac {1}{2}$ If $p_1=\dfrac15, p_2=\dfrac14$, the probability that $C$ wins the game $\dfrac {1}{3}$ Value of $p_1$ so that P($A$ wins) $=$ P($B$ wins) $\dfrac {1}{4}$ Value of $p_2$ so that the game is equiprobable to all the three players $\dfrac {1}{5}$

1 Verified Answer | Published on 07th 09, 2020

Q4 Subjective Hard
$A's$ skill is to $B's$ as $1 : 3$ ; to $C's$ as $3 : 2$ ; and to $D's$ as $4 : 3$: find the chance that A in three trials, one with each person, will succeed twice at least.

1 Verified Answer | Published on 07th 09, 2020

Q5 Single Correct Hard
There are 5 duplicate and 10 original items in an automobile shop and 3 items are bought at random by a customer. The probability that none of items is duplicate, is
• A. ${{20} \over {91}}$
• B. ${{22} \over {91}}$
• C. ${{89} \over {91}}$
• D. ${{24} \over {91}}$

1 Verified Answer | Published on 07th 09, 2020

Q6 Single Correct Hard
X and Y plays a game in which they are asked to select a number from $21-50$. If the two number match both of them wins a prize. Find the probability that they will not win a prize in the single trial.
• A. $\dfrac{1}{5}$
• B. $\dfrac{21}{84}$
• C. $\dfrac{28}{30}$
• D. $\dfrac{29}{30}$

1 Verified Answer | Published on 07th 09, 2020

Q7 Subjective Hard
An industrial salesman wants to know the average number of units he sells per sales call. He checks his past sales records and comes up with the following probabilities.
 Sales in units $0$ $1$ $2$ $3$ $4$ $5$ Probability $0.15$ $0.20$ $0.10$ $0.05$ $0.30$ $0.20$
What is the average number of units he sells per sales call?

1 Verified Answer | Published on 07th 09, 2020

Q8 Single Correct Hard
In a group of $13$ cricket players, four are bowlers. Find out in how many ways can they form a cricket team of $11$ players in which atleast $2$ bowlers are included.
• A. $55$
• B. $72$
• C. $None\ of\ these$
• D. $78$

1 Verified Answer | Published on 07th 09, 2020

Q9 Subjective Hard
There are three events A$,$ B$,$ C$,$ one of which must$,$ and only one can happen$;$ the odds are $8$ to $3$ against A$,$ $5$ to $2$ against B $:$ find the odds against C.

1 Verified Answer | Published on 07th 09, 2020

Q10 Single Correct Hard
The figure above represents four offices that will be assigned randomly to four employees, one employee per office. If Karen and Tina are two of the four employees, what is the probability that each will be assigned an office indicated with an $X$?
• A. $\dfrac { 1 }{ 16 }$
• B. $\dfrac { 1 }{ 12 }$
• C. $\dfrac { 1 }{ 4 }$
• D. $\dfrac { 1 }{ 2 }$
• E. $\dfrac { 1 }{ 6 }$