Answer shown and explanation above! Hope this helps!
Answer: 60 of the patients are boys.
Step-by-step explanation: According to what is described, 5 in 8 patients are girls, then: 8 - 5 = 3, i.e., 3 in 8 are boys.
Mathematically the proportionality is 
If 160 patients have appointments per month and
are boys:
160.
= 60
Per month, 60 boys have appointments at the medical office.
You are looking for the average. To find the average, one adds all terms and divides by the number of terms.
((1/2)+(5/6))/2
((3/6)+(5/6))/2
(8/6)/2
(4/6)
(2/3)
The answer is B) 2/3.
3x+2y=5.44
it's a two variable problem which can't be solved algebraically unless you are given the weight of one of the balls.