probability ka adda

Here i will be posting ques on probability which could prove to be useful 4 every1
Do try to give explanations if u can
options will be given on demand
[1]

Q1
If the papers of 4 students can be checked by any one of 7 teachers , then the probability that all the 4 papers r checked by exactly 2 teachers

80 Answers

11
Mani Pal Singh ·

RITIKA SEE D OPTIONS IN #26

1
MATRIX ·

wat r the options........mani.??........

11
Mani Pal Singh ·

Q2
2 numbers r selected at random 4m 1,2,3,4,5,........100 and r multiplied
then the probability(correct to 2 place of decimals ) that the product obtained id divisible by 3

11
Mani Pal Singh ·

yes it was a mystery
sorry 4 confusing u guys [2]

but sacchi i didnt meant to

1
The Scorpion ·

dats what me n tapan said... 42/343 = 6/49...

well, none of these is correct... rather... E option is correct... [3]

11
Mani Pal Singh ·

Now i am disclosing the solution
I think no one thought like that

the total cases r 74 everyone knows it

the no. of ways of of choosing 2 teachers out of 7 are 7C2

but the no. of ways they can check 4 papers is 24

But it includes 2 ways in which paper will be selected by 1 teacher

So no. of ways become 24-2=14

No. of fav ways 7C2 X14

the prob is 7C2 X14/74 =6/49

so u see which option is correct!!!!!!!!!!!

13
deepanshu001 agarwal ·

((4! /(2!2!2!) + 4!/(3!1!))2!*7C2)/7^4

13
deepanshu001 agarwal ·

B option shud be correct ....

is it......maniboy....

21
tapanmast Vora ·

ye kaise solution hai

kuch samjhao Mrunal

11
Mani Pal Singh ·

WRONG PROCEDURE

I KNOW TUKKE MEIN AAP MAHIR HO
PLEASE GIVE THE RIGHT PROCEDURE!!!!!!!!!!!

1
Ritika ·

OPTIONS!!! i've demanded..hehehehehe..lemme try.

1
Ritika ·

now i'm in a doubt......

1
The Scorpion ·

[11]

can u tell us how u interpret this...!!??? [7]

btw... its value is greater dan one... so its not possible...!!!

1
Ritika ·

LAST ONE 7c2

1
Ritika ·

the answer's not
7C2 X 7C2 X 7C2 X 7C1
7^4
?????

1
The Scorpion ·

Answer is 42/343... from d expression given by tapan, which according to me is correct...!!!

well, whats d answer given...???

11
Mani Pal Singh ·

the options r

(A)2/7
(B)12/49
(C)32/343
(D)NONE OF THESE

NOW I DONT WANT THE ANSWER
NOW I WANT THE SOLUTION


TUKKE MAR KE ANS TO TUM NIKAAL HI LOGE

21
tapanmast Vora ·

ANS : 7C2(2^4 - 2) / 7^4

21
tapanmast Vora ·

hmmmmmmmm point

1
The Scorpion ·

@singh...

if all d papers n teachers are different... then second one is almost appropriate... if they are considered identical... then v need to further solve it...!!!

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