this is about probability?

Question

The success rate for drilling for oil is 10%. If 10 wells are drilled, what is the probability that
a) exactly 3 wells will contain oil
b) all the wells will contain oil
c) none of the wells will contain oil
d) at least 6 will contain oil

Answer 1

1) exactly 3 will contain oil=>
3 contain oil 7 do not contain oil

probability = 10C3 (0.1)^3(0.9)^7
= 120* 0.001* (0.9)^7 = 0.057395 = 5.74%

2) All wells contain oil
probability = 10C10 (0.1)^10 = 10 ^ -10 which is very very less

3) No wells contain oil
10C0 *(0.1)^0*(0.9)^10 = 0.34867844 = 34.86%

4)At least 6 contain oil
P = P(6) + P(7) + P(8) + P(9) + P(10)
= 10C6 *(0.1)^6*(0.9)^4 + 10C7 *(0.1)^7*(0.9)^3 + 10C8 *(0.1)^8*(0.9)^2 + 10C9 *(0.1)^9*(0.9)^1 + 10C10 *(0.1)^10*(0.9)^0 = 0.0001469 = 0.014% Which is also quite low

Answer 2

Your probability distribution is:
n probability
0 0.34867844
1 0.387420489
2 0.193710245
3 0.057395628
4 0.011160261
5 0.001488035
6 0.000137781
7 8.748E-06
8 3.645E-07
9 9E-09
10 1E-10
a) 3 0.057395628
b) 10 1E-10
c) 0 0.34867844
d) P(at least 6) = 0.000146903

Answer 3

Say probability of getting oil is p(o) = 0.1 and probability of not getting oil is p(no) = 0.9

(a) probability of getting oil in exactly 3 wells
= 10C3 p(o)^10-3 p(no)^3
=120 * (0.1)^7 * (0.9)^3

(b) p(E) = (0.1)^10

(c) p(E) = (0.9) ^10

(d) p(E) = 10Cx p(o)^10-x p(no) ^x , Now x can have a value of 6,7,8,9,10 .Find all the values and add it , to get the required probability

Answer 4

i noticed you've submitted lots of probability questions...
i bet it's your assignment.. better do your homework or else you'll regret it!

instead of waiting for the answers.. why wont you solve it first yourself.. then post your answers here.. and then let's see if it's correct or not... in that way... your brain wont be dull >_<

alryt!

Answer 5

how's that homework coming