7.
7 squared gives 49, and it is a prime number.
Answer:

Step-by-step explanation:
This is a conditional probability exercise.
Let's name the events :
I : ''A person is infected''
NI : ''A person is not infected''
PT : ''The test is positive''
NT : ''The test is negative''
The conditional probability equation is :
Given two events A and B :
P(A/B) = P(A ∩ B) / P(B)

P(A/B) is the probability of the event A given that the event B happened
P(A ∩ B) is the probability of the event (A ∩ B)
(A ∩ B) is the event where A and B happened at the same time
In the exercise :



We are looking for P(I/PT) :
P(I/PT)=P(I∩ PT)/ P(PT)

P(PT/I)=P(PT∩ I)/P(I)
0.904=P(PT∩ I)/0.025
P(PT∩ I)=0.904 x 0.025
P(PT∩ I) = 0.0226
P(PT/NI)=0.041
P(PT/NI)=P(PT∩ NI)/P(NI)
0.041=P(PT∩ NI)/0.975
P(PT∩ NI) = 0.041 x 0.975
P(PT∩ NI) = 0.039975
P(PT) = P(PT∩ I)+P(PT∩ NI)
P(PT)= 0.0226 + 0.039975
P(PT) = 0.062575
P(I/PT) = P(PT∩I)/P(PT)

A) If you have 12 dogs and cats (I assume 12 in total) and divide those by two, you get six dogs and six cats. It has to be more dogs than cats, and the sum of those two has to be twelve. So to reach the sum 12, while one number is bigger that the other, the number has to be 7 or more.
66 is the 100%
we can solve this problem by the rule of three.
Therefore:
66------------------------100%
x--------------------------150%
x=(66 * 150%) / 100%=99
Answer 150% of 66 is 99.
Other method:
150% of 66=1.5 *66=99
Answer: 150% of 66 is 99.