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Mathematics: Post your doubts here!

nehaoscar

nehaoscar

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Please explain part ii
I don't get it why to multiply by 7*6*5*4 .... and why not multiply further etc... :/
 
nehaoscar

nehaoscar

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The general rule is X ~ B ( n , p ) and p is the probability of success right...
Then the nos. divisible by 5 are 10,15 and 20
So shouldn't p be 3/12 = 0.25
But then how is it 0.2??
Please explain :S
 
nehaoscar

nehaoscar

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How to find k?
np = 96 and npq = 32
so p = 1/3
q = 2/3
n = 144
I don't know how to find k since no probability is given either ??
 
Anum96

Anum96

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nehaoscar said:
View attachment 58802
How to find k?
np = 96 and npq = 32
so p = 1/3
q = 2/3
n = 144
I don't know how to find k since no probability is given either ??
Click to expand...
For k, n = 9 (1,2,3,4,5,6,7,8,9) ; np <= k ; 9p = k ; 9(2/3) = k ; k = 6 Ans.
leenz98 said:
part 2 anyone please?
Click to expand...
You got u (-2/5,11/5) right? Find its modulus. you get undrt(5). now Iz - uI = IuI will give you z-(2/5,-11.5) Plot that on your graph and make a circle with radius udrt(5). That's it :)
leenz98 said:
s12qp31 need help with q2 2nd part, can't get this right for some odd reason, anyone?
Click to expand...
Just use your answer to part i. Take the product of your answer and 1 + 2x. combine the like terms and you will get the answer. :)
 
Anum96

Anum96

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nehaoscar said:
I don't get it o_O
we found n as 144 but then we're using 9 here??
Which formula is it for the np<k ... np is the mean right?? ...
Click to expand...
For k, n is 9. Since you have to find the probability of success. you just have to equate them. k/9 will be the probability and since you have p as 2/3
So, k/9 equals 2/3 ; 9(2/3) ; 6
Get it?
 
Anum96

Anum96

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nehaoscar said:
No :cry:
Click to expand...
Look. Probability of success here is what? 2/3 right?
Now, The question says that the random variable X is the number of these n integers less than or equal to k between 1 and 9 inclusive. How will you find the probability of success here? You need the value of k right? if k was lets suppose 4. You would just right the probability as 4/9. But you dont have k. So it will be k/9.
2/3 and k/9 are both probabilities of success so just equate them.
How about now? :)
 
zahra azam

zahra azam

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when a polynomial f(x) is divided by x - 3,the remainder is -9 and when divided by 2x-1,the remainder is -6.find the remainder when the f(x) is divided by (x-3)(2x-1)(4).

Anum96
Plz help
 
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