A bag contains 6 black and 8 red balls. A ball is drawn at random from the bag. If the ball drawn is black, a coin is tossed twice otherwise no coin is tossed. What is the probability to get two heads respectively on the coins.

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18 Nov 2014 Probability A bag contains 6 black and 8 red balls. A ball is drawn at random from the bag. If the ball drawn is black, a coin is tossed twice otherwise no coin is tossed. What is the probability to get two heads respectively on the coins.: OPtion
1) 1/8
2) 1/4
3) 3/7
4) 1/7
5) 3/14
6) 3/28
7) 2/7
8) 1/2
9) 1/3
10) 1/48; Correct Option: 6 Best Solution (60)

Jayanta Dutta 10 years AGO

1 black ball from 6 black balls can be selected as 6C1 so the prob is- 6C1/14C1

now 2 heads can be obtained 1 ways i.e. {hh,ht,th,tt}
so prob is -1/4;

so the prob of getting two heads while drawing a black ball is-

6/14*1/4
i.e-3/28 option.(6)

Like? Yes (6) | No (2)

Deepak prajapati 10 years AGO

(6/14)*(1/4)=3/28

Like? Yes (3) | No (2)

ARJUN PRASAD 10 years AGO

6/14*1/2*1/2

Like? Yes (2) | No (1)

SOHOME DAS 10 years AGO

probability of black ball = 6/14
probability of two consecutive head = (1/2)* (1/2) = 1/4
all along final ans will be = 6/14 * 1/4 = 3 / 28 (Ans)

Like? Yes (1) | No

prem kumar chaudhary 10 years AGO

(3/7)*(1/4)=3/28

Like? Yes (2) | No (1)

Rahul 10 years AGO

probability of getting the black ball = 6C1/14C1 = 3/7

probability of getting both the coins head = 1/4

combined probality = (3/7) * (1/4) = 3/28

Like? Yes (2) | No (1)

Aman Gupta 10 years AGO

6/14x1/4=3/28

Like? Yes (1) | No

santosh kumar patel 10 years AGO

to get head , we must choose the black ball
that's why
probability of black ball and two twice head is
6/14*1/2*1/2=3/28

Like? Yes (1) | No

Mani Shankar 10 years AGO

chance of drawn ball is black : 6/14
chance of getting to heads in two toss are : 1/2*1/2
so chance of whole event will be : 6/14*1/2*1/2 = 3/28

Like? Yes (1) | No

Divesh Ranjan 10 years AGO

probability of 1 black ball drawn = 6/14
and getting heads after tossing twice= 1/2*1/2=1/4
hence (6/14)*1/4=3/28

Like? Yes (1) | No

veeranjaneyulu 10 years AGO

6/14x1/4

Like? Yes (1) | No

MAHARAJAN.G 10 years AGO

total number of balls=14
probability of getting black=6c1/14c1=6/14
coin is tossed twice so n=4
{ (h,h) , (h,t), (t,h) , (t,t) }
probability of getting two heads is=1/4
total probability of getting two heads =6/14*1/4=3/28

Like? Yes (1) | No

mradul kumar 10 years AGO

for first we find probability for getting a black ball :
6c1/14c1=6/14
now we calculate prob of getting two heads if drawn ball in black:
6/14*1/2*1/2=3/28
so option 6 is correct..

Like? Yes (1) | No

Swagatam Kumar Das 10 years AGO

Problty to slct one black ball is 6/14
And prblty of 2 head is 1/4
So ans is (6/14) *(1/4) =3 /28

Like? Yes (1) | No

shubham 10 years AGO

because probability of black is 6/14 and for one hed is 1/2 for first head and for second head 1/2 that makes it 3/28

Like? Yes (1) | No

Shreya Tiwari 10 years AGO

Probability of drawing a black ball is 6/14 = 3/7
After then the probability of getting two successive heads is 1/2 * 1/2 = 1/4
Net probability = 3/7 * 1/4 = 3/28

Like? Yes (1) | No

Kushagra Tiwari 10 years AGO

Probability of drawing a black ball is 6/14 = 3/7
After then the probability of getting two successive heads is 1/2 * 1/2 = 1/4
Net probability = 3/7 * 1/4 = 3/28

Like? Yes (1) | No

Abhishek Vishwakarma 10 years AGO

Probability of drawing a black ball is 6/14 = 3/7
After then the probability of getting two successive heads is 1/2 * 1/2 = 1/4
Net probability = 3/7 * 1/4 = 3/28

Like? Yes (1) | No

Maniratnam 10 years AGO

6/14*1/2*1/2 = 3/28

Like? Yes (1) | No

ranjithreddy 10 years AGO

Probabilty of getting Black is=6/14.
After that if a coin is tossed twice,the probabilty of getting head two times is 1/4.
Therefore the final probability is=(6/14)*(1/4)=3/28

Like? Yes (1) | No

Supriya Mondal 10 years AGO

probability of getting black ball from the bag is=6/14
and probability of getting one HEAD from the coin is=1/2
so answer will be=(6/14)*(1/2)*(1/2)=3/28

Like? Yes (1) | No

Anshul Shrivastava 10 years AGO

(6/14)*(1/4)
=3/28

Like? Yes (1) | No

Chirag Ranjan Lahiri 10 years AGO

Probability for black ball = 6/14

Probability for getting two heads respectively = 1/4

so total = (6/14)*(1/4) = 3/28

Like? Yes (1) | No

Devendra Kumar 10 years AGO

6/14*1/4=3/28

Like? Yes (1) | No

Parag Wagh 10 years AGO

6/14*1/2*1/2=3/28

Like? Yes (1) | No

Rahul Dasharath Vayale 10 years AGO

3/7*1/4=3/28

Like? Yes (1) | No

RAMAKRISHNA 10 years AGO

p(bLack ball)*p(heads)=3/28

Like? Yes (1) | No

ADARSH GAURAV 10 years AGO

3/28 is the answer.

Like? Yes (1) | No

Sanu Panji 10 years AGO

P = (6/14)*(1/2)*(1/2)
=3/28

Like? Yes (1) | No

zafar 10 years AGO

probability of selecting black ball is 3/7, Probability of 2 heads is 1/4. 3/7*1/4=3/28

Like? Yes (1) | No

khushboo goenka 10 years AGO

(6c1*1/4)/14c1

Like? Yes (1) | No

surya 10 years AGO

probability of getting black ball out of 6 black and 8 red balls
is 3/7
if then a coin is tossed twice in the first case getting head is 1/2 and second case is also 1/2
then final probability is 3/7*1/2*1/2=3/28

Like? Yes (1) | No

alok meher 10 years AGO

probability of getting a black=6/(6+8)=6/14
probability of getting two heads respectively = (1/2)*(1/2)=1/4

so,probability of getting two head after the ball drawn=
(6/14)*(1/4)=3/28

Like? Yes (1) | No

Hemadri 10 years AGO

Total balls=14
probability of taking black ball=6/14=3/7
probability of getting heads on the coin=1/4
Probability=(3/7)*(1/4)=3/28

Like? Yes (1) | No

Jigyasa Kumar 10 years AGO

Answer is .1071

Like? Yes (1) | No

Siddharth 10 years AGO

the probability of getting a black ball is 6/14 multiplied by the probability of getting two heads i.e. 1/4 which results in 3/28!!

Like? Yes (1) | No

abhilasha 10 years AGO

The answer os 3/28.

Like? Yes (1) | No

abhishek narayan 10 years AGO

6/14*1/2*1/2

Like? Yes (2) | No (2)

swati kunj 10 years AGO

probability of getting black ball=6c1/14c1=3/7
no of event of coin is tossed twice={hh,ht,th,tt}
so probability of getting 2head=1/4
probabitlity of getting black ball and 2head=3*1/7*4=3/28

Like? Yes (1) | No (1)

Himanshu Mittal 10 years AGO

Probability of taking black ball = 6/14
Probability of coming two heads consecutively= 1/4
So, total probability will be (6/14)*(1/4)=3/28

Like? Yes (1) | No (1)

Anirudh 10 years AGO

6/14 probability for the ball to be taken out
now 1/2 for head for first time
1/2 head for second time
and the event will be completed when all three hapeen and soit will be multiplied
6/14*2*2
=1/8

Like? Yes (1) | No (1)

PAWAN KUMAR 10 years AGO

Probability of getting black ball = 6/14
Probability of getting two heads = 1/2 * 1/2 = 1/4
Since coin is tossed after getting black ball,so,
Probability of getting two heads = 6/14 * 1/4 = 3/28 Ans.

Like? Yes (1) | No (1)

SUBHASH TULSYAN 10 years AGO

6/14*1/2*1/2

Like? Yes (1) | No (1)

kamal 10 years AGO

way of choosing a black ball from bag= 6/14=3/7
now black ball drwan so we have to toss now
getting head probability in first time=1/2
and in seond time=1/2
so probability of getting head=3/7*1/2*1/2=3/28

Like? Yes (1) | No (1)

Akash Verma 10 years AGO

probability of getting one black ball is 6c1/14c1=3/7
now probability of getting two head=1/4
so ultimate probability=3/7*1/4=3/28(Ans)

Like? Yes (1) | No (1)

k srinivas 10 years AGO

3/28 is answer
p(getting black)*p(two heads)
6/14 *(1/2*1/2)
3/28

Like? Yes (1) | No (1)

Arijit Das 10 years AGO