N=8
If you set 2/3 equal to n/12 then you multiple 3 by 4 to get 12. So you have to multiple 2 by 4 to get N.
Answer:
P(≥ 7 males) = 0.0548
Step-by-step explanation:
This is a binomial probability distribution problem.
We are told that Before 1918;
P(male) = 40% = 0.4
P(female) = 60% = 0.6
n = 10
Thus;probability that 7 or more were male is;
P(≥ 7 males) = P(7) + P(8) + P(9) + P(10)
Now, binomial probability formula is;
P(x) = [n!/((n - x)! × x!)] × p^(x) × q^(n - x)
Now, p = 0.4 and q = 0.6.
Also, n = 10
Thus;
P(7) = [10!/((10 - 7)! × 7!)] × 0.4^(7) × 0.6^(10 - 7)
P(7) = 0.0425
P(8) = [10!/((10 - 8)! × 8!)] × 0.4^(8) × 0.6^(10 - 8)
P(8) = 0.0106
P(9) = [10!/((10 - 9)! × 9!)] × 0.4^(9) × 0.6^(10 - 9)
P(9) = 0.0016
P(10) = [10!/((10 - 10)! × 10!)] × 0.4^(10) × 0.6^(10 - 10)
P(10) = 0.0001
Thus;
P(≥ 7 males) = 0.0425 + 0.0106 + 0.0016 + 0.0001 = 0.0548
Answer:
- The system of equations is x + y = 85 and 7/20x+2/5y=31
- To eliminate the x-variable from the equations, you can multiply the equation with the fractions by 20 and multiply the other equation by -7.
- B-She used 60 minutes for calling and 25 minutes for data.
Step-by-step explanation:
It is always a good idea to start by defining variables in such a problem. Here, we can let x represent the number of calling minutes, and y represent the number of data minutes. The the total number of minutes used is ...
x + y = 85
The total of charges is the sum of the products of charge per minute and minutes used:
7/20x + 2/5y = 31.00
We can eliminate the x-variable in these equations by multiplying the first by -7 and the second by 20, then adding the result.
-7(x +y) +20(7/20x +2/5y) = -7(85) +20(31)
-7x -7y +7x +8y = -595 +620 . . . . eliminate parentheses
y = 25 . . . . . . . . simplify
Then the value of x is
x = 85 -y = 85 -25
x = 60
Answer:
breadth = 12
length = 36
Step-by-step explanation:
let the breadth be 'x'
length = 3x
p = 2l + 2b
96 = 2(3x) + 2(x)
x = 12
