Answer: The answer is 30%.
Step-by-step explanation: Given that there is a group of 10 light users and 10 heavy users. We are to find the probability that exactly 3 of the 20 users are HIV positive.
We have the following four possible cases -
(i) All 3 are light users.
(ii) 1 is a light user and 2 are heavy users.
(iii) 2 are light users and 1 is a heavy user.
(iv) All 3 are heavy user.
Since there is a 45% chance of a light user to be HIV positive and 55% chance of a heavy user to be HIV positive, so the required probability is given by
Thus, the probability is 30.
It's "commutative property," which says that (for addition/multiplication) order of the operator doesn't matter. For eg, 3 * 5 = 5 * 3.
Associative property (again, of multiplication and addition) means that it doesn't matter how you solve an expression if the same operand is used and some numbers are grouped. For eg. 3 * (5 * 4) = (3 * 5) * 4.
Since a square is equal on all sides divide the perimeter by 4.
40/4 = 10 the length of one side is 10 yards
Answer:
The number of parents who volunteered to bring refreshments is 16.
Step-by-step explanation:
The information provided is:
N = 84
n (S) = 35
n (S ∩ R) = 11
n (R) = 1.5 × n (S' ∪ R')
Compute the value of n (S ∪ R) as follows:
![n(S\cup R)=n(S)+n(R)-n (S\cap R)\\\\n(S\cup R)=n(S)+[1.5(N-n(S\cup R)]-n (S\cap R)\\\\n(S\cup R)=n(S)+1.5N-1.5n(S\cup R)-n (S\cap R)\\\\2.5n(S\cup R)=n(S)+1.5N-n (S\cap R)\\\\2.5n(S\cup R)=35+(1.5\times84)-11\\\\2.5n(S\cup R)=150\\\\n(S\cup R)=\frac{150}{2.5}\\\\n(S\cup R)=60](https://tex.z-dn.net/?f=n%28S%5Ccup%20R%29%3Dn%28S%29%2Bn%28R%29-n%20%28S%5Ccap%20R%29%5C%5C%5C%5Cn%28S%5Ccup%20R%29%3Dn%28S%29%2B%5B1.5%28N-n%28S%5Ccup%20R%29%5D-n%20%28S%5Ccap%20R%29%5C%5C%5C%5Cn%28S%5Ccup%20R%29%3Dn%28S%29%2B1.5N-1.5n%28S%5Ccup%20R%29-n%20%28S%5Ccap%20R%29%5C%5C%5C%5C2.5n%28S%5Ccup%20R%29%3Dn%28S%29%2B1.5N-n%20%28S%5Ccap%20R%29%5C%5C%5C%5C2.5n%28S%5Ccup%20R%29%3D35%2B%281.5%5Ctimes84%29-11%5C%5C%5C%5C2.5n%28S%5Ccup%20R%29%3D150%5C%5C%5C%5Cn%28S%5Ccup%20R%29%3D%5Cfrac%7B150%7D%7B2.5%7D%5C%5C%5C%5Cn%28S%5Ccup%20R%29%3D60)
Now compute the value of n (R) as follows:
![n (R) = 1.5 \times n (S' \cup R') \\\\n (R) = 1.5 \times [N-n (S \cup R)]\\\\n (R) = 1.5 \times [84-60]\\\\n(R)=16](https://tex.z-dn.net/?f=n%20%28R%29%20%3D%201.5%20%5Ctimes%20%20n%20%28S%27%20%5Ccup%20R%27%29%20%5C%5C%5C%5Cn%20%28R%29%20%3D%201.5%20%5Ctimes%20%20%5BN-n%20%28S%20%5Ccup%20R%29%5D%5C%5C%5C%5Cn%20%28R%29%20%3D%201.5%20%5Ctimes%20%20%5B84-60%5D%5C%5C%5C%5Cn%28R%29%3D16)
Thus, the number of parents who volunteered to bring refreshments is 16.
