A bag contains 5 white, 4 red and 3 black balls. A ball is drawn at random from the bag. Find the pr

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08 Apr 2016 Probability

A bag contains 5 white, 4 red and 3 black balls. A ball is drawn at random from the bag. Find the probability that it is not black.

OPtion

1) 1/3
2) 1/5
3) 1/4
4) 3/4
5) 3/5
6) 2/3
7) 1/12
8) 1/9
9) 1/7
10)1/8

Solution

Total number of balls in the bag = 5+4+3 = 12
As we don't want a black ball, it means that the number of favorable outcomes = Total number of white and red balls = 5+4 = 9
Therefore probability of getting a ball other than black ball = 9/12
= 3/4
Option 4)

Correct Option: 4 Best Solution (21)

JANARTHANAN RAM   8 years AGO

Total number of balls=12
Black balls=3
Other colour balls=9
Probability(not black)=9/12=3/4

Like? Yes (13) | No   

Meenakshi   8 years AGO

Total number of balls in a bag=5+4+3=12
Probability of the ball drawn that is not black = 9C1=9
So , 9/12=3/4
Option 4)

Like? Yes (4) | No   

maneet minocha   8 years AGO

total no of non black balls=5+4=9
total no of balls =12
hence prob of non black ball=9/12=3/4

Like? Yes (3) | No   

SANTOSH KUMAR DASH   8 years AGO

Total no. of balls= (5+4+3)=12=n(S)
The ball to be drawn will not a black ball. So either the ball would be red or white.
Let E1= event of drawing a white ball
E2= event of drawing a red ball

So P(E1 or E2)=P(E1)+P(E2)=5/12 + 4/12=9/12=3/4

So option 4.

Like? Yes (2) | No   

dev   8 years AGO

Total outcomes = 5 + 4 + 3 =12
required outcomes = 5+4 =9

so probability = 9 / 12 = (3 / 4)

Like? Yes (1) | No   

Dinesh kumar sah   8 years AGO

The probability of finding a drawn ball is black is 3/12=1/4.
and the probability of finding a drawn ball is not black is 1-1/4=3/4 Ans
ie option (4) is the correct answer.

Like? Yes (1) | No   

mcamanjeet   8 years AGO

probability to find black ball = no of black ball/total no of black balls
=3/12=1/4
probability to ball is not black= 1 - 1/4
= 3/4

Like? Yes (1) | No   

Bidhubhusan Biswal   8 years AGO

Total number of balls=12
black balls=3
probability=(12-3)/12=9/12=3/4

Like? Yes | No   

sani musa tsoho   8 years AGO

let n(s) be the total number of sample space, i.e n(s)=4+5+3=12

let W,R, and B be an event of getting White balls, Red balls and Black balls respectively, then

prb(W)=n(w)/n(s)= 4/12; prob(R)=n(R)/n(s)=5/12 and
prob(B)=n(B)/n(s)=3/12

by using axiomictic defination of probability we've

prob(of not black)=1-prob(B)
=1-3/12
= 9/12
=3/4
therefore the prob. that it is not black is 3/4

Like? Yes (1) | No (1)  

ANANTHA PADMANABHAN T   8 years AGO

totally there are 12balls out of which 9 balls are not black in colour so the probability is 9/12=3/4

Like? Yes | No   

NISHANT KUMAR   8 years AGO

P(not black)=P(red+white)
P=[n(red)+n(white)]/total no of balls
P=(5+4)/12
P=3/4

Like? Yes | No   

vani   8 years AGO

probability of gettig black is 3/12 ie 1/4 so not getting black s 1-1/4 ie 3/4

Like? Yes | No   

Vikas William   8 years AGO

total ways of taking 1 ball is 12c1
ways of taking 1 black ball 3c1
so probability of taking 1 black ball is
3c1/12c1
hence probability of no black ball is
1-1/4=3/4

Like? Yes | No   

Asheesh Jain   8 years AGO

Total no of ball=6+4+3=12
The probability that the ball drawn is black=3/12=1/4
The probability that the ball drawn is not black=1-1/4=3/4

Option 4) is the correct answer.

Like? Yes | No   

Mahesh   8 years AGO

simple,there are 12 chances ,by excluding the black out of 12,we get 9/12 => 3/4

Like? Yes | No   

Devendra Marghade   8 years AGO

Probability of a ball taken out to be black=3/12=1/4
So probability of being not black=1- (1/4)=3/4
Option 4)

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Nikhilesh kumar   8 years AGO

5+4=9
5+4+3=12

9/12=3/4

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sugayathri   8 years AGO

probability that is not black=n(e)/n(s)
5+4+3=12

12c1

n(S)=12

5w+4r=9

n(E) =9c1


= 9/12
=3/4

Like? Yes | No   

Praveenkumar P Kalikeri   8 years AGO

Ans :- (5c1 +4c1 )/(5+4+3)
= 9/12
=3/4

Like? Yes | No   

vini   8 years AGO

Probability of getting white ball = 5/12
Probability of getting red ball = 4/12
Probability of getting black ball = 3/12
Probability of getting ball white or red = 5/12 + 4/12 = 9/12 = 3/4

Like? Yes | No   

Mukund Manohar   8 years AGO

Required Probability = 9C1/12C1
=9/12
=3/4

Like? Yes | No